As Emile Smith Rowe's easy strike hit the back of the net with David de Gea stricken on the ground in front of his unguarded goal, Old Trafford held its breath.
Thirteen minutes into an enthralling encounter between Manchester United and Arsenal, more than 70,000 supporters inside the stadium turned to each other and their phones for clarity, after the most bizarre and controversial goal of the season, possibly in the Premier League's history.
For a moment, the bemusement extended to the stadium's principal television studio wedged between the Stretford End and Sir Alex Ferguson Stand, level with the 18-yard line of the penalty area.
In the cramped space, tucked behind a camera with a platoon of technicians, Sportsmail was watching Alan Shearer, Patrice Evra and Thierry Henry make sense of the circus below, as we went behind the scenes with Amazon Prime Video, who streamed the game live.
For an instant, even the pundits, with 977 Premier League games between them, look stunned into silence like the rest of Old Trafford. But a technician bursts the bubble.
'What's going on?' he shouts as the pictures stream through the monitors and the ball nestles inexplicably in De Gea's goal, while both sets of players appeal to referee Martin Atkinson.
The former pros immediately spin round and run to the TV screen propped up against the wall in front of a bank of cameras to grab a second look.
Manchester United's goalkeeper David de Gea was down injured when Arsenal's Emile Smith-Rowe scored after 13 minutes
As the stadium held its breath, pundits Alan Shearer and Thierry Henry ran to the monitor for a slow motion replay
Smith Rowe scores Arsenal's controversial opener after just 13 minutes at Old Trafford, with De Gea lying injured on the turf
Shearer calls it first. 'That's a goal,' declares the former Blackburn Rovers, Newcastle and England striker as a replay reveals that De Gea's own team-mate, Fred, stood on the keeper's ankle and left him in a heap on the goal line. 'They can't disallow that.'
He's right. And the others agree, reluctantly in the case of Evra, who made 278 Premier League appearances for United, and one suspects with a little satisfaction for Henry, who scored 175 top-flight goals for Arsenal.
A discussion immediately ensues over fair play, across a table laden with biscuits and delicious lemon pies. If the goal is given with De Gea incapacitated, will Arsenal allow United to score to even things up and gift them a goal?
'No chance,' observes Evra, ruefully, as the Arsenal players begin to embrace. 'Look at how they celebrate.'
Confusion ruled on the pitch where Arsenal players initially did not celebrate and immediately appealed to the referee
Any thought of Arsenal gifting Manchester United a goal faded as the Gunners' players rejoiced at their good fortune
It was then Manchester United's turn to appeal to Martin Atkinson, led by midfield duo of Fred and Scott McTominay
Even in these early stages the half-time discussion is beginning to take shape.
But Evra wants to know if a foul has been given. High up in the stand, match commentator Peter Drury and the former Rangers and Scotland striker Ally McCoist have to sort out the scene in real time.
'That's very, very awkward for the referee,' Drury told an audience expected to top three million streaming on Amazon with many millions more around the world, via the various feeds serving the Premier League's extensive customer base.
'Let's see if Martin Atkinson gets the whistle to his lips,' says Drury.
The TV studio at Old Trafford is perched above the 18-yeard line of the penalty area in which the bizarre goal was scored
Shearer and Henry had front row seats of the goal and the reaction of the United players as they went on to win the game
Even as he's saying the words, a super slow motion replay from a camera inside the goal is queued and ready to roll by the match director, sat 180 miles away in a production centre the technicians reassuringly call The Rock.
It answers Evra's question: Atkinson did not blow his whistle and allowed the play to develop so that VAR could intervene.
'He has to give the goal,' Drury's co-commentator, McCoist, correctly declares without hesitation.
The pundits have established within a few seconds what takes VAR more than three minutes to conclude. And as ever, the viewers at home know a whole lot more than those at the ground.
The game resumes but Shearer and Co remain in animated discussion with production staff, who are sat in one of four broadcast trucks outside the stadium, planning the half-time running order.
Some 135 engineers and production staff were at Old Trafford to stream the game backed up by more than 100 elsewhere
Meanwhile, video analysts studying the feeds of the 25 match cameras around the pitch are finding the best shots to tell the story the ex-pros are now describing.
Under its deal with the Premier League, Amazon Prime Video covers all 10 games in two mad, midweek match rounds each season in December. And last night was one of their best performances, so far.
A five-goal thriller, a big penalty shout, a goal that will one day feature on a Question of Sport and the arrival of United's new boss, Ralf Rangnick, gave the Amazon team a challenge, but also a great opportunity to showcase their capabilities. And they took it.
It is a mind-boggling operation, which begins in earnest six hours before the game kicks off, when the 135 technical and production staff, who are working onsite, receive their final orders.
Manchester United's interim manager Ralf Rangnick (R) watched his new side play Arsenal, with Amazon Prime Video ensuring three cameras could be trained on the directors' box to be sure to capture an image of the man of the moment
With news breaking that German coach, Rangnick, had been granted a work permit to take over at Old Trafford from caretaker boss, Michael Carrick.
At a production call at around 2.30pm, the producer, Christian Potter, makes it clear he is desperate for images of the new man arriving at the stadium.
'Find Ralf Rangnick,' Christian Potter orders his teams as he wraps up the meeting.
United had been tight-lipped about when and where Rangnick might appear, other than to confirm he would watch from the directors' box later that night, so two cameras are sent out around the ground on Rangnick Watch to catch his arrival.
And three are in position to spot him in the posh seats once the match kicks off.
Two hours later Potter has the pictures that will open the show at 7.30pm. They are not great, Rangnick is obscured as he gets out of his car, 'but it's the news value', Potter rightly declares and they will do.
Commentator Ally McCoist has proved the darling of Amazon Prime Video Premier League coverage and Peter Drury (R) spends eight hours prepping for a Premier League fixture
At this point there is no sign of 'The Talent', which is the ubiquitous title for the pundits in the broadcast industry. The former players do not arrive until 4pm for an evening Premier League game, with the exception of the unlikely star, McCoist.
The Glaswegian is famous among the production staff for his last-minute arrivals. But he has proved to be the darling of Amazon's coverage so far, with the viewers, pundits and staff.
McCoist doesn't have an agent. The production team have his mobile number and he deals with them directly, even while changing the tyre on his car at the side of the road on one occasion.
'He should be prescribed on the NHS, he's brilliant,' says an admiring production staffer, stood outside the talent trailer awaiting the Scot's arrival at a fashionably late 5.30pm.
Amazon Prime Video's presenter, Simon Thomas, prepares for the TV broadcast at Old Trafford in the 'talent trailer'
Ex-players and old friends Thierry Henry and Patrice Evra enjoyed their usual lively debate on the white leather sofas
'Aye,' laughs McCoist, when he welcomes Sportsmail into the trailer, known as a Vroom with A View, a few minutes later. 'But what for? That is the question….'
McCoist, who scored 355 goals for Rangers in a 22-year career is a bundle of energy, good humour and simply loves the game, which explains his popularity. A roar went up from Evra, Henry and Shearer when he burst into the 'Vroom'.
'I love it, man,' says McCoist as he sits chatting on the white, leather sofa inside. 'What is there not to love?'
But what does he put his popularity down to? 'I think people realise that I realise that I am the luckiest man alive,' he says. A few minutes with 'Coisty' and you really do feel better.
The talent trailer, called a Vroom with a View, includes a sofa, swivel chairs, make-up room and toilets so the pundits can prepare at football stadiums before their broadcasts across the country. Pre match briefings are done in the vehicle
Despite his stellar career and celebrity status in football, McCoist is well-grounded. As he arrives at Old Trafford a friend who has just done a 10-hour shift at a car plant texts him to ask sarcastically, 'You out to work, then?'
'It is amazing', admits McCoist, laughing. 'People may be saying 'he is a jammy b******', but at least he knows he is a jammy b******'... What is there not to enjoy?'
McCoist's enthusiasm is infectious, as he prepares to head up to the gantry to join Drury.
'It's the best seat in the house, you see everything,' says McCoist, who admits he feels the pressure prior to kick off.
However, he is super-sharp in commentary, calling the goal and a later penalty when Martin Odegaard brought down Fred in the penalty area after 70 minutes, even though Atkinson waved play-on.
