Venetian - The river is: 5-7-8-6-4 and he instantly said "Nice hand."...as he MUCKS his hand!

Picked up AA and 3 bet a $25 bet to $50 from MP. Over checked the flop of 5-7-8 as did the 3rd opponent. Turn 5-7-8-6. It was checked to me. I bet $50 and next guy folded. 1st guy thinks and thinks and finally says "I'm all in". This would cost me about $200 (pot is about $200 now). My senses tell me to call. I call! Before dealer flips over the river, I ask the guy "You have a straight?” "Nope." as he shows me (and the whole table) his JJ. I show him my AA. The river is: 5-7-8-6-4 and he instantly said "Nice hand."...as he MUCKS his hand! Dealer picks up the guy's mucked cards and mixes them up with the other cards. Someone else mentioned it's a split pot – there’s a straight on the board! Dealer asks if he showed the hand. The guy tried to plead he tabled the hand. He asks for a floor ruling. The floor comes over (and sees my AA and him without cards) and says they’ll check the tape and if they can clearly see his JJ then it will be a chopped pot. They reviewed the tape and ruled in my favor. He had to give me the pot and $255.00 more – my stack. Wow, what a hand!