If I understand it right, 7SD will probably get away with the F-bombs as long as they didn't talk about fucking. That is, "fuck" as an exclamation is not as verboten as "fuck" as a verb. It has to do with indecency vs. obscenity, or something like that.
But didn't somebody end up getting fined when Bono said used "fuck" as an expletive that time? I think the FCC applies the rule as it chooses, and if it wanted to screw FMU it could use Andy's exclamation (which was very reasonable under the circumstances) to do so.
But it probably won't.
I think the greater issue is that, if a terrestrial listener heard by chance and decided to complain, even defending against the FCC would place a huge burden on the station. You're right that the rules are vague for a reason, I bet so that the FCC can be used as a bludgeon when convenient.
I think something this happened a little while back on Coffee Break for Heroes and Villains - Noah played a CD that hadn't been marked as unsafe for radio, just barely missed the dump button after an F-bomb was dropped, and some jerk in West Orange or somewhere filed a complaint, even after receiving an apology from Noah and the station. But everyone seems to think it will all blow over.
Oh, back to the topic - I love Tom for raising almost six figures for WFMU, but I also love Bronwyn C. for getting all excited over breaking the $4k mark for the first time ever. The disenfranchised have a home!