Only thing I can think of is that they didn't think a train would form on Zig and once on they couldn't jump off or look suspicious. Then when JM took the lead they had no reason to jump off.
Or
They started off with only 2 ES, which seems a bit low to me, and Cat was turned last night to evil. Which would make more sense since some of the clues seem to clear me. I thought at 1st in his haste to get me out he was trying to make me look bad but worded it wrong.
Though with there only being 2 ES it would leave a lot of room for us to hang ourselves and let them hide among us.