The answer is: no, they are not that dumb.
It is more probable that he dumped her after they had sex, so she got revenge by crying ‘rape’.
One of these days men will realize that “no sex outside of marriage” is the only way to be entirely safe from false accusations of rape.
One exception would be to have immunity if you had a “Mutual Consent” form, signed, witnessed and notarized 24 hours before the event. Yeah, I know, ain’t gonna happen.
But it would provide the guy with immunity. It would also make a whole lot of people stop and think, “Is this really a good idea?”