Just as a woman shouldn't trust her boyfriend with her birth control, the same should be applied to when a man shouldn't trust his girlfriend with his birth control. If he had used the proper precautions, he wouldn't be in the current predicament. Condoms, spermicide, holding the condom on before flushing it afterwards are just several examples. There's also the option to get a vasectomy and if you wish to have a kid, putting your little fellas on ice.
Despite what you pointed out, he still could have used a condom and flushed it afterwards. Is it entirely his fault? No. However, he should have kept that possibility in the back of his mind if she was past a certain age that she might try something.
Especially when there are women who openly admit that they will do anything to have a child of their own:
http://www.dailymail.co.uk/femail/ar...#axzz2KgoZRohp