Recently on the Dungeon of the Swamp king missions my Parry's have not always triggered, I think only on lunging attacks. They are starting from my side and after moving are in front of me. it has probably happened 3/4 times now, will try to get a screenshot next time it happens.
If it's a map that had mud pit, chances are you were in it. Mud and acid users tend to be able to- and enjoy- spamming them. S'why I tend to focus on clearing them out first, if possible. [Though I think I managed to Duck the one in Alet Zhav a few times, which was pretty handy. I may be thinking Cave In, though, been a bit.]
Considering Mud Pit doesn't target characters and Cave In does, I'm guessing you're thinking of the latter.
I figured as much when I added the note, but the affected tiles look similar enough that with my limited abilities of recollection, I wasn't entirely sure. Either way, those mages like to fight dirty~~