I can relate to that druid, as I heal a lot in dungeons.
Too many times, the tanks chain pull without any regard for the healer's mana, or if anyone gets left behind.
When there's a lockout mechanic before the boss, the tank should wait for others to reach the place, buff up, get mana, and only then, pull the boss.
Too many times, I see noob tanks that think that chain pulling and rushing through the dungeon automatically makes them awesome tanks.
If they get on my nerves too much, I let them die. Then, the hunter's pet can tank instead of them; sometimes with better results.
Yes, I know I am a terrible person.