Yep, I've definitely seen this happen, and clicked continue only to have the character I'm talking to act as though I'd said something I hadn't. I didn't realise the bug was intermittent though, and have just ploughed on regardless.

I'll watch out for it more carefully in future.

"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"