I was playing 2-3-5 poker game (NL) - only me and another player were in hand. His last action was raising $150 on the river which I called. 
He then showed his cards and said "good call, I missed my flush". He had "8" high card, no pair or anything. Dealer mucked his cards and move the pot (about $600) towards me - I waited a little and then slowly passed my cards to dealer [ I didn't show my hand].

Immediately after I collected the chips, the other player complained and said I cannot win the pot because I didn't show my cards.

They called supervisor and they watched the camera, they decided to give the whole pot to other player because I didn't show my cards but he did (although he had only 8 high).


my question - 
  I waited for dealer signal to see if I need to show my cards, but he was already shipping pot to me. - the other player actually mucked his hand, he just didn't say it, even when dealer mucked his hand he didn't complain.


  also since dealer already made decision and hand is over, can they watch the camera and change the dealer decision?


Thank you very much,
-Yusef