Thomas,
I have a lot of respect for you, and what you do, and I don't envy your position. How many times are you at a table when one of these situations occur? I remember, back in the day, that it was a rare occasion when I actually witnessed one of these screw-ups. I'd have a dealer in the box that may have caused the mistake, and a situation that I had to evaluate with second hand information.
Players need to protect their hands. There is entirely too many occasions when players release their cards when they shouldn't. My advice is to teach players to keep their hands on their cards when they are all-in and don't have any chips left to protect them. It's very easy to do. I'm sorry but, unless a hand is properly tabled, or 100% identifiable...the hand is dead and like the rule says: there is no redress. How can any poker player that ever read a rule book ever forget that word? The first time I heard it was over 50 years ago, and it's still the only time I"ve ever used it!

As far as the reflex reaction from my dealers: I hate it when a player folds, and the discarded hand just sits there. Kill that damn hand before he changes his mind and catches me bluffing! Remember, a hand that is protected remains live and a winning hand, that was properly tabled should be the only one that can be pulled from the muck.
The next thing you know, someone will get the idea to use a discard rack like they do in black jack.
They hit the muck...they're dead!