This is easily the dumbest idea in the history of Fallout. I'm playing the St. Louis level in Fallout Tactics today, and I decide to take Harold the Ghoul along. Not only because he's one of my favorite characters from the series, but also because he's good with a sniper rifle and his excellent repair skill works well with the APV you're forced to drive throughout the mission. I spend half an hour inching along, gradually working my way past minefields and waves of heavily armored Super Mutants, then manage to rescue the lost Brotherhood squadron and drive them back to the entrance. I get a ton of EXP for completing the mission, and Harold levels up. Then he dies. Instantly. Thanks to this perk dealing random damage on level up he goes from full health to 0, and because I'm playing on Tough Guy mode I have to restart the entire mission just to keep him on my team. Even if I let him die, I couldn't get any of the expensive repair kits in his inventory back. Why? Because he died while in a vehicle, so there's no corpse to loot from. What in the world was Micro Forte thinking while developing this game? We're they trying to make Ghouls as useless as possible, even though you're forced to go through a difficult and annoying sidequest just to unlock them? At least Deathclaws get a benefit (double HP) when they level up. This just really breaks the pacing of the gameplay for me.

Oh, the fact that you can only set the driver of the vehicle to anyone but the character with the highest Pilot skill (my Big Guns specialist) makes this level much more difficult than it should be. Just saying.

I remember that quest. The most difficult one in the game for me. I had a sniper team, no heavy weapons, and I tried again and again to get through that bottleneck where the path goes west and then north near the trenches, just before the BOS team you need to rescue. Could not do it. Tried the approach from the south, through the minefield. Tried the approach from the west. Those two super mutant groups on the plateaus always killed me. Their damned rocket launchers. I was stuck on that quest for days. Gave up... came back... gave up... came back. Finally did kill those two SM fire teams. I must have tried a dozen times. I wasn't even on Tough Guy. Not an easy game.

That really svcks about Harold. I've never used any of the ghouls playing the game, so I never ran into your problem. All I can do is commiserate.

I found this on the wiki: http://fallout.wikia.com/wiki/Fear_the_Reaper. It says his hit points should only be reduced to a critical level, not zero. So why the hell does he go all the way to zero? Tough Guy doubles your XP, doesn't it? Does Harold go up more than one level? Maybe the Reaper hits him twice?

It's a Trait.

Ive never had this problem, always seemed to work just fine for me. ~are you fully patched?
Get him out of the vehicle before the end of the level so you dont need to worry about not being able to loot him if he dies.

If you dont want your Big Guns guy to drive, dont put him in the vehicle and next time someone levels give them a few extra points in Pilot so their skill exceeds his. Problem solved. Pretty sure there were even skill books for Piloting at the start of this level, they could even make the difference for you.