With a sideline of yet more confirmation that Cameron is now able to make her own decisions, as her statement of her original mission to the psychiatrist means this is still current, she just manages - chooses to - override it.

I read that line quite differently. I think that over the episode Cameron is actually recapitulating her development through three personalities: first Allison, then the original Terminator Cameron who was sent to infiltrate and kill John, and that she doesn't snap back to the current Cameron until the actual point where she nearly kills Jodie.