I tagged both:
I let Bob know that Lynn’s in danger. Fatherly obligations outweighs philanthropic ones.
Transmit the SOS. If Bob loses his kid to superheroing, he may say “Fuck the cape.”
I want him to keep doing his good works. If I didn’t tell him about Lynn, (a) he might get really pissed off and kill me, and (b) he might give up superheroing entirely. It is reasonable for someone to care more about, and want to prioritize aid to, loved ones.