We had an interesting situation happen in the Fall Classic High Roller event. During level 3 of the tournament, where the blinds were 75/150/a25, Connor Joseph Drinan opened preflop to 500 from early position. It folded around to the button player, who accidentally exposed a 
when mucking his hand. When the action came around to John Gordon, sitting in the big blind, he had the impression that he received a walk, and showed the 
while jokingly saying “I’m all-in”. The dealer informed him that there was still a player in the hand, Connor, which came as a complete surprise to John. The floor was called over to make the ruling on this hand, and although the rule is very clear about this kind of occurence, regardless of the situation or magnitude of the buy-in, the tournament director was consulted to confirm the ruling. In the mean time, given that a 6 was already exposed, Connor mentioned that if John is binded to commit his stack in the middle, he will likely make the call.
The final ruling forced John to go all in, and his 
was called by the A9o of Connor. The board didn’t pair either player, and Connor doubled his stack of 31K, leaving John with 1,600 chips behind. John was visibly frustrated with the situation, and understandably so, but the floor had to stick with the rules in this situation.
John has managed to bounce back since, and is now sitting on a healthy 34K stack in level 7!