During one scene Gemma Foster (played by Suranne Jones) was seen frantically trying to call her teenage son Tom (Tom Taylor) as she desperately tried to work out where he was.
However, as the GP tried to get in touch with Tom, viewers spotted that the mobile phone screen was still displaying apps and had not dialled at all.
Another shot showed Gemma leaving a voicemail for Tom but the screen appeared to be in the gallery app.Related articles
One eagle-eyed viewer took to social media to point out the hilarious continuity error with one person posting: "#DoctorFoster making phone calls through her photo gallery. Utter magic that."
However, most viewers were left in shock over the incredible season opener as they flooded to Twiter to praise the episode with one person posting simply: "SO GOOD! #DoctorFoster."
"Simon clearly playing games. Great opening episode. Cool it on the heavy soundtracks though. It's gripping enough! #teamgemma #DoctorFoster," wrote a second.
BBCAn eagle-eyed Doctor Foster fan spotted a technical gaffe
BBCGemma's phone appeared to be stuck on the home screen