? about floor decision regarding cards hitting muck

[kassdog]

I was playing Majestic Star in Gary, IN at 1/2NL. Came to showdown heads up. After all betting was done player 1 shows his hand with something like 2 pair or something. Player 2 then had a cleary better hand and flipped them and threw them on top of the muck pile facing up. He was in the 8 seat so he cleary had to throw a great distance to make the muck pile.

Player one thought he won because he thought player 2 mucked his hand when they hit the muck. dealer shoved pot towards player 2 and player 1 complained and floor was called. Floors decision was so long as the cards were face up he won but advised to only flip in front to not cause further confusion.

Now my understanding was that as soon as his cards hit the muck the hand was dead? thoughts