Eddie had alot of pride.
Eddie had just had his ass handed to him and was humiliated.
Eddie was trying to teach Vince how to gamble and hustle on the road and was completely destroyed at his own game.
Eddie was Vince's backer and told him who to play and when to play them and the LAST thing Eddie wanted to hear at that moment from Vince was "nice try Eddie, let me play him, he can't beat me".
I agree with this. The way I saw it was that Eddie was feeling like playing and advertised that he was looking for a game with the hundred on the rail move (seeing this movie at 18 I honestly thought that this was a real thing that people did to look for games).
Who knows how long Eddie was there and drinking, remember "Ted" (Grady) was called to play and Eddie took him down then we see Eddie playing Amos.
I honestly think that Amos let it out at the end of it where he got the serious expression and said quietly, "do you think I need to lose some weight?" It was a classic double entendre that real players everywhere would get immediately. (At 18 I didn't get it immediately).
And the rest is as you stated it. To me Eddie had just gotten hustled and he was pissed that he didn't see it. And the REASON he didn't see it is because he had been out of the pool HUSTLING part of the game for 25 years. He did his liquor hustling and some backing but he wasn't big time and he wasn't a road man any more.
Remember in the Hustler the goal was to go legit and be the best. So this was the turning point in the Color of Money where Eddie realized that he was wrong for trying to turn Vincent into another version of himself and relive those days vicariously.
At that moment when he was so skillfully hustled he realized that this was exactly what he was training Vince to do and the life he didn't want to lead. It wasn't about snapping off Amos. It was about the basic dishonesty of it, each pretending to be someone else and not just playing hard to win.
He then realized he still had the fire to try and be the best and we see that the movie is not at all about Vince and Carmen, it's all about Eddie and his road to redemption on the table.
The scene at Gunther's was brilliant. The whole movie really was brilliant. And I thought Tom Cruise played the part perfectly. The cocky but still naive player turned into a devious hustler and a worthy match for conniving Carmen was played perfectly. Raging to want to play his best, like Eddie wanted to at Vince's age, but stifled by a stake horse/road partner forced to hold back, until he became the hustler he didn't want to be.
Every time I watch it I think I learn something new.