Your thinking is quite ridiculous. This is LIVE poker, there is more to the game than betting. Part of the game is observing what is going on, reading the board, and acting on all of the information available. If you fail to do so then you are not playing as well as someone else and your results should be effected by that.

There is a major difference in tabling your hand at a showdown because you believe you have a winner and misreading the board and mucking your hand. This is part of the ACTION and part of your job as a player. ACTION in live poker is any task performed at the table, including properly showing down your hand.

Under the rules in most cardrooms (all that I know of)if in a tournament you told a player he should recheck his hand at the river to see if he may have a winner during a hand in which you were no longer involved you would be given a penalty for breaking a rule. If this occurred in a cash game you would be reprimanded and warned by the floor that this is not acceptable behavior. I'm not sure where you get your ideas from but they really only work in an online game where the computer handles the showdown and it is impossible to accidentally muck a winner.

A hand is not complete until the pot has been awarded AND the next deal has begun. If a player tables his cards at a showdown it is everyone's ethical responsibility (as stated in most cardroom rule books) to make sure the pot is correctly awarded, if a player has not tabled his hand at a showdown it is everyone's responsiblity to keep there mouths shut about the hand until the pot has been awarded and the next deal has begun. There is no grey area there. This is how every poker room works under their rulebook's that I have ever seen or played in.