I don't fully understand the hate towards 278.
Originally she did not agree to the plan. Even though 50-50 chance sounds like a good idea and is mathematically the best chance those in the front had, she did not agree to jumping while it was still technically 301's turn.
She said it herself. She did not jump untill she had no one else to hide behind. Selfish? Sure, but that's 4.56million for you.
Also, no one forced 301 to jump. The players still had 'plenty' of time left and they were in the midst of discussing who would jump next. He jumped mid-discussion. And I say that as someone who was rooting for him since ep 1.
The other players were just too keen to keep to the only jumping once deal. She would have been a full blown idiot to not take advantage of that. I wish she just owned her decisions and not try to gaslight Mai.