Accidentally take, sure. Accidentally consume? Maybe one bite. Unless there were some odd circumstances, like mental deficiency, or nearly identical meals, beyond one bite is very difficult to believe.
I accidentally consumed a coworkers yogurt cup once (and told her/replaced it as soon as I realized). I had started daring a different coworker and she had said something like "you can eat my yogurt in my yellow bag at the front-left of the fridge". Unfortunately, we had 2 fridges in the break room at the time...
Another HN user offered a story (that doesn't seem super unlikely) that would disagree with you: