I understand the desperation of seeing over a hundred grand slipping away, but the guilt he was laying on all three of them and the fact he said he'd 'swear down' and 'swear on anything you want' like, presumably, his mother, wife, children's lives? or whatever close relatives he has, was another level of betrayal.
All that said, he worked through the game and it did feel wrong for Meryl in particular to pick up thirty something thousand when she was still terminally bemused even after he said he was a Traitor.