[Mr Rick]

Wow. Great situation. Close call.

I would call it a muck. And award the pot to hero. The villain was clearly getting rid of his low flush turned sour.

I wish dealers at FW would all grab mucked river cards and bury them quickly. Some do. Most don't.

I would give muppet a time out/table change/stern warning and if they ever did it again a ban whose length would be dependant on how frequently they played (i.e. if they came once a week I'd ban them a month or two).