Don't feel too bad -- we've all mistakenly lit money on fire before...whether it's misclicking online or misreading a situation like this live.
Kind of a funny story, a few years ago during the series a friend of mine was playing 5/10 at Venetian and called an opponents all in on 66xxx with A6. Turned out the other guy was bluffing, and after making the call my friend opened his hand but inexplicably through his cards face down into the muck while his opponent still had his cards. The pot was over 4k and the floor (correctly) ruled that my friend essentially folded and awarded the other guy the pot. At least you didn't do that