Was Linnea still descending when Bob got to her? If so, that's a horrific complication for anybody, let alone a student.
I wouldn't advise a rescue diver in this situation to ditch their own weight. If they lose contact with the victim, they're going to be in an uncontrolled ascent. Ordinarily, ditching the victim's weight isn't a priority at depth. The idea is to control your and their ascent, though emphasizing getting them buoyant.
If this was a recovery and not a rescue attempt, I could see taking the time to remove lead from wherever it was hidden on the body. If there was ditchable weight in the BCD (a debated point, not clear in the suit) a quick thinker might have ditched it in a rescue.
But we've got an AOW student rescuing a grossly overweighted diver with a shrink-wrapped dry suit at depth in dim light and possibly both are descending and/or at a depth the rescuer has never seen. There comes a point where you have to say I can't complicate this for rescuers by becoming the second victim.
One of the things that surprised me as a student and again as an instructor is how much emphasis is put on the emotional well being of the rescuer. If Bob is out there lurking on Scubaboard, I'd tell him the same thing I tell Rescue students: There's no such thing as a bad rescue attempt if the rescuer is not another victim. You did something, and that's 100% better than nothing.
In reading reports about students dying, I ask myself "could this have happened to my student?" In this case, the answer is unequivocally no for the following reasons:
1. Nobody dives a dry suit with me unless they are experienced with it, certified for it, or had a pool session with me.
2. A student who couldn't inflate their suit isn't diving.
3. No matter how much lead the shop gave the student, I wouldn't let a woman with Linnea's build dive with 40 pounds in salt water, let alone fresh.
4. Lead never goes in dry suit pockets. It unbalances trim badly. I've slipped a few pounds in non-ditchable BCD pockets, but these divers still had 90% of their weight on a belt and ditchable weight pouches. And I've only done this if a pre-dive weight check had them under-weighted.
Damn this story makes me angry. And I don't swear.