Words words words
Although there were about a dozen possible ways for him to escape if he decided to think about them. Because if you could say anything about Nathan Bateman, you could say that his ego was so huge that he would not allow himself to be trapped in his house even if the security alarms are tripped. But since Caleb's fate is not the point of the movie, worrying about whether he lived or died in the long run isn't important--Ava was willing to leave him behind to die, and that's what matters.I was glad when her master was killed.
I was less glad when she left the guy who was trying to help her escape starve to death.
I personally think there was no particular reason her escape plan required her to leave Caleb, since bringing him along would logically even help her escape and pretend to be human, but she was thinking emotionally rather than logically, and her emotions--much like those of Westworld hosts--were to get the hell away from these people as quickly as possible.