They crashed at Roswell because they had just spent the prior 3 days abducting showgirls in Las Vegas. No one is immune to the after-effects of girls, cocaine, and dry martinis.
Changing my tag line thank you very much
As someone who was once married to the daughter of a Las Vegas show girl, I find your theory entirely possible.
There are offspring, I can testify.
I was married to an alien lol