I recall this happened in the WSOP a few years ago, when the, "lumberjack" guy had a flush but did not bet. He was penalized one orbit of blinds. I recall that a straight flush would be possible with the board cards, so I was puzzled since he didn't technically have the "nuts".
In that case, they would have got the ruling wrong then. It has to be the nuts on board.
I have only heard this rule being enforced in tournaments, more specifically the WSOP. I don't have a problem with it, but it usually penalizes those that aren't trying to angle the game.
I saw a guy on YouTube just call with the nuts, and that's against the rules. Is the rule in place so that players don't go easy on friends or confederates?
I hope that's only for Hold'em games. In Omaha 8 you often want to call with a nut low if you're going to get quartered.
Players who always bet and/or raise at almost every opportunity, will check all the way to the river.