Home game ruling - was this guy a douche?

[EasilyFound]

In my home game, if a player at showdown mucks his hand (meaning that the cards are thrown into the muck face down so nobody sees them), I do not require the other player to show a hand to be awarded the pot. In other words, a player can surrender a pot at showdown.

The rule at showdown is cards speak, regardless of what anyone says. If one player's cards are shown, another player cannot be awarded the pot without showing his or her cards.

I'd be happy to hear what other people do if they follow a different rule.