Caleb was sexually attracted to a robot he perceived to be a grown woman. Eva even told Caleb her age: 1. And when she undressed at the end, she looked pre-pubescent.

If Caleb had drawn clear boundaries with her (like any responsible adult would've) and remembered the simple truth that the only reason he was interacting with her was to administer the touring test, he would've survived.

They should've sent a pimp instead of an intellectual...