I would say he just lacks experience to know and play his defenses.
We are one of the few classes, not to mention being a clothie, that could be the last few standing when everyone drops.
Feels like a bad azz hero when you get a boss down with only a tanks and heals up with you and a few dps.
Or heals get deleted in M+ but in the last few seconds BOOM full health, rez someone and beat timer.