Don't stress! If for some reason you can't save the person in time, the game will "reset" back two weeks, so you can try again. But you'll lose any levels or progress you gained in those two weeks, so keep that in mind...

That boss is a pain in the ass, though, so I know what you're going through xD My girlfriend ended up going off and doing something else while I struggled with that boss, and she usually watches me play constantly xD;