I took the time to answer a user's question today, submitted it and …
Nothing. It disappeared. No warning, nothing to suggest I'd done anything wrong.
Possibly/probably this is because I hadn't signed in but if that's the case, the UI shouldn't allow me to type an answer and/or at the very least should warn me that it's about to toss everything I've written into the trash (and at that point offer to let me sign in before it blows everything away).
Whatever you do, NEVER blitz the text an answerer may have spent a fair amount of time researching/entering (luckily that wasn't the case this time, but it's left a bad taste/distrust)