I have trouble feeling bad for the guy. He was paid what he had agreed to.
We here in SV have evolved a culture and a set of business practices that do a much better job of compensating us fairly. We make good cash money, and we tend to get a share of the success when things get big. It's not like we as individuals were clever enough to negotiate all of the details; it's a system mostly other people worked out over time.
But we're very lucky in that people with our talents and skills are still much rarer than business types would like. That's not true with artists, and the music industry's default practices, especially then, were generally shitty. There's no reason this guy shouldn't get as fair a shake as we do.
(And before anybody has a personal story of not getting a fair shake: yes, that sucks, which is exactly why you should want to see systemic changes that minimize that happening to others.)