First, guys, lay off with the ad hominems, wouldja? Sheesh.
We recently played through a situation in our game that had some interesting similarities and differences. A group of assassins attacked us, and the party sorcerer was thwacked down to 0 hit points. I, playing a druid at 1/2 hitpoints, stepped forward to heal the sorcerer. He got away, but the next round, the assassins managed to knocked me down to -18 hit points. Oops!
To make matters worse, the sorcerer proceeded to betray the rest of the party to the bad guys over the course of the next several rounds. It was the culmination of a months-long plot thread. Eventually the sorcerer repented and rescued the surviving party members from the evil cultists to whom he'd betrayed us, but not before several companions were tortured.
When my PC was eventually reincarnated, he was full of guilt: had he not healed the sorcerer, the betrayal wouldn't have happened, and his companions wouldn't have been tortured by evil cultists.
We resolved this all in-character. Although we were originally all in favor of executing the treacherous sorcerer, we listened to his story, talked with him -- and watched in horror as, finally repenting of his actions, he was immolated by a curse placed on him by the demon he'd be serving. We eventually reincarnated him and placed him on party-probation, keeping him on a very short leash.
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The lessons:
1) Druids really can die quickly if they're on the front-lines. The party druid feared for his safety rightly.
2) Nonetheless, if you're gonna die as a PC, it's pretty fun to die in a self-sacrificing way. Major karma points are earned for dying in the process of saving a friend.
3) Party conflicts are natural and good, if they're handled correctly. Talk out-of-character about whether everyone wants to keep playing their PCs, and about how the PCs feel about what's happened; then play through it in-character, with an eye toward helping everyone advance their characters' personalities.
In this situation, let's assume that the psychic warrior is resurrected. I'm imagining him coming on gangbusters toward the druid, specifically blaming the druid for his death, and demanding assurances that it's not going to happen again. Other party members will likely back him up.
Maybe they'll tell the druid that next time he hesitates to heal someone, he'll be forced out of the group. They might demand that he procure several cure critical wounds potions to give to the psychic warrior at no cost, so that the latter doesn't need to rely on the former in the middle of battle.
And this can all be fun. It can be a chance for the group to see how party dynamics work.
If it's handled in a "punish the player" fashion, however, it's gonna suck for everyone. DO NOT do that.
Daniel