There are ways to prove that. Besides, doing it unprotected is a shared decision.
- - - Updated - - -
How is it fundamentally unequal?
She could have used any form of protection or just not had sex without a condom. The cause is fundamentally EQUAL.
Therefore the effect should be equal too, she either takes a morning after pill or abortion or he gets to "abort".
The man is not solely responsable for a pregnancy or the lack thereof. Get condoms (yes, they exist for females), keep em closed, use the pill, use IUD, demand the use of a condom. So many options.