Synthflesh lab monster on table doesn't stand up to be killed so room can't complete

I have had this happen twice where one of the mobs that stands up from the tables in the Synthflesh lab do not stand up before the mob that summons them is killed and then the room cannot be completed. The only way to leave the room is by portaling or logging out.

Clip: https://www.twitch.tv/garfm/clip/HonestJoyousHedgehogVoteNay-plF1QlkRz9o1KM03