Diana was apparently having dinner with a fellow GBBO baker when she passed out and hit her head the night before they began filming the fifth episode in the spring.
As a result of the fall, the 69-year-old Women's Institute stalwart says she has now lost her sense of taste and smell and decided she no longer wanted to take part in the competition.
"I fainted - which I have never done - and bashed my head, severing my olfactory nerve. So I have now lost my sense of smell and most of my taste," she explained.
Following Wednesday night's episode four, Diana found herself at the centre of a Twitter storm after being accused of "sabbotaging" Iain Watters' Baked Alaska showstopper.
Viewers saw Diana remove his ice-cream from the freezer and it appeared she had left it on the side and not told him, meaning it melted. Iain was then sent home after throwing his melted pudding in the bin.
However, Diana has since insisted the ice-cream was left on the side for no more than 40 seconds - a claim which the BBC later backed up in a statement.
GBBO judge Paul Hollywood and host Sue Perkins also took to Twitter to defend Diana, who is the oldest contestant ever to have appeared on the show.
As things reached fever pitch yesterday afternoon (28 August), it was then revealed Diana had quit the show days after the Baked Alaska drama had happened.
But while conspiracists claimed her decision to leave GBBO was due to '#BinGate', as it has since been dubbed, it seems her reason to leave was unconnected - and quite concerning in terms of Diana's health.
Holding back tears yesterday, Diana told her local radio station that what viewers had seen was actually a result of "very bad editing".
She explained: "I found Iain's ice-cream in my freezer, I asked whose it was, took it out and Iain took it away. It was not out of the freezer for more than 40 seconds.
"It wasn't long enough to do what it did. I think it was very bad editing. There is nothing I can do about it." She added: "I've no idea why they did that and it's very unfortunate."
By Thursday morning, the BBC had received more than 500 complaints about the episode.
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