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I still dont get it. If he thought his opponent has nothing, why didnt he check and call any bluff bet?

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According the the audio interview on cardplayer, he led at the pot on the river because he didn't want Antonius to get a free showdown with a hand like 33 or 44. So when Antonius raises, Joe just went through every possible hand and decided that since he had the ace of diamonds (which is very important because he didn't think Antonius could raise with a small flush) that Antonius simply had to be bluffing. It's not crazy, just a good solid read.

So to answer your question, he can't just check/call with ace high because it was essentially Antonius's river raise that gave Joe the information that he was bluffing.