The 64-year-old TV presenter - who has been standing in for Piers Morgan on the ITV breakfast show - made sure he went out with a bang on his last day by bringing GMB to a stand still in the hunt for his missing earpiece.
Co-host Susanna Reid, 49, told viewers: “You know they call Wednesday ‘Hump Day’ - Bill is really having one of those Wednesdays. You’d forgotten to put your teeth in earlier and were having trouble reading.”
Turnbull agreed: “And I’ve forgotten my contact lenses and I’m having to wear glasses. And then my earpiece popped out and we can’t find it.”
A clip was shown of the entire GMB production team searching the studio floor during the ad break for Turnbull’s inner earpiece, used for producers to communicate with the hosts during the show.
Co-presenter Ranvir Singh even checked Turnbull’s ear and he said: “Stop fiddling with me. Keep your hands to yourself!”
The small earpiece was eventually spotted by a member of the team when the show was back on air - between the pages of Turnbull’s script.
Turnbull exclaimed: “Unbelievable!”
Turnbull and Reid have been reunited on screen, having worked on BBC Breakfast together for over a decade before Reid left to host the ITV morning show in 2014.
In November 2019, Turnbull had appeared as a guest on the programme when Reid asked him if he would return when Morgan "has been incapacitated".
“I would love to, name the day. I wouldn’t do it full time. It is a little bit stressful and stress is not good for cancer, but every once in a while would be great," he replied.
Turnbull is currently battling prostate cancer. He made the announcement in March 2018 having learnt of his diagnosis in 2017.