What is different ? Evans didnt intend to rape the sweet innocent girl as he maintains she consented to everything.
One is one person wanting sex and taking it without regard to the woman's vulnerable state. If he does what he wants to do, a woman is used for sex without the ability to consent.
The other is someone wanting to drive home, if he does what he wants to do, he gets home.
Evans wanted sex with the girl his friend pulled, he got what what he wanted, regardless of what she wanted or was capable of wanting.
McCormick wanted to drive home, he did not set out to take a life thinking he could find someone who was desperate to be euthanised couldn't find them, so killed to unwilling kids instead.
Surely you can see the difference?