It says much about modern times that on hearing a commotion next door, Tom Penn – acting 'purely out of instinct' – reached for his smartphone and pressed record.
The phone call to police would come later. First, Mr Penn, 30, wanted evidence that might prove 'important'.
Such a reaction had nothing to do, of course, with the fact that those engaged in the crockery-breaking barney just after midnight on Friday were none other than Boris Johnson and his 31-year-old girlfriend Carrie Symonds – or that the sleuthing Mr Penn and his wife Eve Leigh are avowed Remain supporters.
Under fire: Tom Penn and Eve Leigh, who live in the same block as Carrie Symonds in Camberwell, south London, said he heard screaming, banging and then silence in the early hours of Friday morning, which caused him to call the police
Miss Symonds is said to have been heard screaming at Mr Johnson to get out of the flat in a Victorian House in Camberwell, south London that she bought last year and lives in with her lover (pictured)
Both are playwrights and Ms Leigh, described as a New York-born 'Leftist', once gleefully boasted on Twitter that she had given Boris 'the finger'.
The neighbour who recorded a late-night bust-up between Boris Johnson and his girlfriend Carrie Symonds has revealed tonight he called police because he feared for the safety of the people inside the flat.
Tom Penn, who has lived at the flat in Camberwell, south London, for over a year, said he heard screaming, banging and then silence in the early hours of Friday morning, which caused him to call the police.
Mr Penn, who said he voted remain in the EU Referendum in 2016, declared he went public with the recording because he believes a future prime minister should be held to account over his actions.
At a hustings event in Birmingham today, Mr Johnson, 55, flatly refused to answer questions about the explosive row with 31-year-old Miss Symonds - who did not attend the event.
Mr Penn released a statement tonight where he said he called police after hearing shouting from Miss Symonds' flat.
He had been on the phone to a takeaway delivery driver at the time as he went downstairs to collect the food.
The 34-year-old had a leading role in a theatre project called Brexit Stage Left – a festival of plays held in January and partly funded from a £1 billion EU cultural project.
Did the couple record the bust-up, then, because they hoped to inflict on the Boris bandwagon a damaging blow? No, says Mr Penn.
The truth was they were genuinely concerned that something 'dangerous' might be happening in the flat.
In fairness to him, it did sound quite a quarrel.
Another neighbour said she had 'never heard anything like it'.
But as it transpired, there was nothing sinister unfolding inside the Symonds-Johnson first-floor flat in Camberwell, South East London.
And certainly by the time police arrived, peace had been restored. Joking ensued. All was well.
But the brief episode, which also reflects, perhaps, our poisonous political times, does raise questions.
Most curious of all is what the couple did – and why they did it – after they were assured by police that there was nothing to worry about, that no one was hurt, no crime had been committed and that there was no cause for further action.
At this point many in their position might have slunk away, faintly embarrassed they had dropped their neighbours (with whom they share a tiny communal landing) in it with police.
Yet instead of letting the matter rest, Mr Penn rang The Guardian.
Not just to tip off the paper, but to tell his story, a detailed account of the night's events.
Were the couple hoping to make a few quid?
Hardly. The Guardian doesn't normally engage in cheque book journalism and, in any case, they don't appear hard-up.
Speaking at a hustings in Birmingham on Saturday, Boris Johnson did not mention the issue in his opening comments, insisting: 'We need to get Brexit done... and I am the right man'
The Tory leadership hopeful and possible future prime minister shares the home with his partner Carrie Symonds (pictured at his leadership launch earlier this month)
Ms Leigh was raised in a £15 million New York home and her father was American composer Mitch Leigh who wrote the 1965 Broadway musical Man Of La Mancha, which included the huge hit The Impossible Dream.
'In the early hours of Friday morning, I answered a phone call from a takeaway food delivery driver. At the same time, I heard what sounded like shouting coming from the street.
'I went downstairs, on the phone to the driver, and collected my food. On the way back into my flat, it became clear that the shouting was coming from a neighbour's flat. It was loud enough and angry enough that I felt frightened and concerned for the welfare of those involved, so I went inside my own home, closed the door, and pressed record on the voice memos app on my phone.
'After a loud scream and banging, followed by silence, I ran upstairs, and with my wife agreed that we should check on our neighbours. I knocked three times at their front door, but there was no response. I went back upstairs into my flat, and we agreed that we should call the police.
'The police arrived within five minutes. Our call was made anonymously, and no names were given to the police. They subsequently called back to thank us for reporting, and to let us know that nobody was harmed.
'To be clear, the recordings were of the noise within my own home. My sole concern up until this point was the welfare and safety of our neighbours. I hope that anybody would have done the same thing.
'Once clear that no one was harmed, I contacted the Guardian, as I felt it was of important public interest. I believe it is reasonable for someone who is likely to become our next prime minister to be held accountable for all of their words, actions and behaviours.
'I, along with a lot of my neighbours all across London, voted to remain within the EU. That is the extent of my involvement in politics.
'The unpleasant things being said about myself and my partner, and some quite frankly bizarre and fictitious allegations, have been upsetting for not only us, but also for family, friends and fellow Camberwell neighbours, who are currently being harangued by the media. I would ask that you leave private citizens alone and focus instead on those who have chosen to run for power within the public eye.
'The attempts from some areas of the press to instead focus their stories on us, and in particular my wife, have been eye-opening, and very alarming. I would encourage anyone to record any instances where they feel concerned for another person's safety.'
According to Mr Penn, they rang the paper because the matter was of 'important public interest'.
The unfortunate events might possibly never have happened were it not for Mr Johnson's runaway success in the Tory leadership race.
On Thursday, he saw off arch rival Michael Gove to leave him facing Jeremy Hunt, over whom he has a commanding lead.
Might he have allowed a night off from his alcohol-free diet to celebrate? It would seem so.
A loud altercation – involving red wine – between Mr Johnson and Miss Symonds could be heard coming from their flat after midnight.
According to The Guardian, which has listened to the recording, Mr Johnson was heard refusing to leave the flat and telling his girlfriend 'to get off my f****** laptop before a loud crashing noise.
The paper claimed that Symonds then said Johnson had ruined the sofa with red wine.
'You just don't care for anything because you are spoilt. You have no care for money or anything.'
Friends of Mr Johnson and Ms Symonds told The Mail on Sunday the laptop was being used to search the internet for solutions to remove wine stains from upholstery.
At first Mr Penn and Ms Leigh weren't named by The Guardian, which initially tried to disguise Mr Penn's gender, though gave it away.
The paper reported that the couple called police as a last resort after receiving no response from inside the flat.
It quoted Mr Penn, who was waiting for a takeaway, as saying: 'I'd heard the screaming and shouting that sounded like it was from the street before I went to get my food.
'It became clear as I returned that it was coming from inside.'
The recording, he said, was made 'purely out of instinct'. He added: 'I had my phone on me because I'd gone to pick up a Deliveroo so I was on the phone to the Deliveroo driver.
'If I saw someone who I thought was in danger on the street I would start filming while seeking help. I was inside my own flat hearing shouting, screaming and banging so I pressed record.
Boris Johnson attended the Uxbridge and South Ruislip Conservative Association Summer Drinks in Uxbridge just an hour after reports of the blazing bust-up between him and his partner
Mr Johnson attended the the Uxbridge & South Ruislip Conservative Association summer drinks this evening, an hour after reports of the row with Miss Symonds emerged
'It felt like if there was something dangerous happening that having a recording of it would be important as evidence.
'The screaming maxed out the volume of the microphone on my phone through two doors, which is why we became concerned.'
After the couple dialled 999, police in two cars and a van arrived in minutes, but left after receiving assurances the altercation was over.
It is a pocket of London normally associated with bohemian types rather than aspiring Prime Ministers. Yet Boris Johnson lays his head in Camberwell, sharing his 31-year-old girlfriend Carrie Symonds's flat on a quiet tree-lined street that features a mix of handsome Georgian properties and social housing.
Once one of the South London's toughest neighbourhoods, these days Camberwell attracts creative Londoners drawn to its lively arts scene and diverse community.
But locals in the Labour- dominated area say it remains 'edgy in parts' and is certainly a step or two down from the would-be PM's previous abode.
Before moving in with Miss Symonds, the former Foreign Secretary lived with wife Marina Wheeler in a £3.75 million Grade II listed home by the Regent's Canal.
Ms Symonds's flat is a stone's throw from the estate where ten-year-old schoolboy Damilola Taylor was knifed to death in 2000.
Neighbour Ross Standaloft has written a withering rap song in which he describes Mr Johnson as a 'Tory dumb dumb' with 'big floppy hair and an ever-flapping jaw'.
'There
