The Aces hand was so frustrating to watch, but at the same time summed up why poker is so interesting - people aren't robots and under intense pressure will make bad decisions, which creates debate and entertainment for the viewer.
Fwiw, in my live poker experiences, when players open jam live in those spots as played (taking into account Rimmer is a rec player) it's because they're scared to see another card, restricting their range to pure bluffs, semi bluffs with draws/weak pairs, or commonly over pairs when there's a flush draw out there, which made the Aces fold all the more baffling.
Given the money jumps I can only assume he didn't want to put himself at risk of not getting a top 3+ cash (think there was five or so left at that point?). Irrational logic I know, but if he's playing above his means I can imagine caution got the better of him.
Agree with every word of that. It's so easy when we are on the Rail, & can see the hole cards.