What could make you get into a fight with your fellow gambler? And would you agree at anytime to double cash with your fellow gambler to place a bet using his account, on the notion of increasing the potential win.
Nothing. I would walk away even if money was involved. I have seen someone die from a sucker punch during a heated argument over money. If a fellow gambler and friend tries to play a fast on me because I used his account for betting and her won, I would walk away. There are several other subtle ways of getting me money back from him even without their knowledge. Sun Tzu in his book the Art of War said something similar to that the best victories are the ones fought without any bloodshed and in this case without a fist fight.