was largely because of (and somewhat understandable) the stress he was under. COINTELPRO did what it was supposed to do. The shit worked. Huey became incredibly paranoid and fearful. He became a drug addict. Those things can't be disputed. The stuff about the penthouse with the guards roughing people up, sexually assaulting people -- that was stuff I hadn't heard of before this doc. But Huey was in nonstop state of intense stress for years, and I have no doubt that changes you. For the worst.
Eldridge on the other hand, was always "off." I guess Eldridge did get off a bit light though, they didn't show who he became in the 80s...