I think I understand why Christa would have went ahead and given Kendra the 10K because she probably knew that Az was going home. Jay had told her to short her the 10K (the treasure was worth 50K divided 4 ways and they all got 12.5K but Jay dreamt up a plan so that Christa would get an additional 10K by lying to Kendra and only giving her 2.5K with the 10K promised later when she buys the pardon from her... that part added for those who can't load it). Anyways, I think I understand where she was coming from. The pardon would have saved her if the crew had mutinied AND since she knew that Az was going home, she didn't want everybody hating her for going back on her word since Kendra wouldn't be going home (even though Jay assured her she would be!).
How can he be surprised? Poor naive guy, seriously. Jay cannot be trusted and the sooner they all realize that the better. And what was up with Nessa buddying it up all of a sudden with Jay...wow....guess since her shipboard romance is gone she's trying to find a new one?