I dont necessarily thing its her responsibility for him to be protected and vise versa. Bottom line, YOU dont want babies, YOU take the precaution. Condoms can rip easily so guys should see that they ARE taking the pill or something.
just a bit of advice: just like it's a girl's responsibility to make sure that the guy she's sleeping with uses a condom, it's generally a good idea for a guy to make sure that the girl he's sleeping with is using a primary form of birth control (the pill, the shot, the ring or the patch) so that combining her method with your condom makes the chances of pregnancy or STDs very very low. So consider it your job from now on to look for partners who are responsible enough to protect themselves twice (pill AND condom) and you won't have to be so afraid if a condom breaks.....just a bit of advice, because unfortunately if a girl gets pregnant she generally takes the guy for every penny he's got in child support, so you want to protect yourself as well. hope this helps :)
It's ultimately her choice but yes, you should recommend plan B if she is comfortable with it. pre-ejaculatory fluid (pre- c*u*m) has enough sperm to impregnate a woman, and it doesn't matter if you urinated before you had sex or if you didn't finish, you would still have leaked enough to get her pregnant without a condom, which means that whatever leaked from the condom also has the potential to get her pregnant. To be on the safe side, she should take plan B, but because the risk is small (yes it is possible she got pregnant but the chance isn't HUGE) don't pressure her too much and let her make the choice. I wouldn't say it's "highly unlikely" that she's pregnant, but I wouldn't panic yet.