In every game of Texas Hold 'Em that I have ever played, whether online, in private or in a casino or poker room, if any player in the action is all-in and there can be no more betting (that is, if there is no more than one player in the hand who is not all-in), all players involved must immediately flip up their cards. There is no concealing of hands in an all-in showdown. If other people have had experience otherwise, I am quite frankly surprised.
Folding does not equal a bad call. ... Forced showing eliminates that bit of strategy.