I actually had in mind that a player might make such a slip on purpose (the character would make it by accident).

Your response, though, points out how difficult it would be (at first) to tell player-mistake from character-mistake.

I'm sure we're all willing to give you latitude to fix player slips. -- Though, of course, we are like as not to be confused by them. (The price of having readers hanging on your every word and obsessively hitting the refresh key!)