Tanks, Watch Your Healer's Mana

I queue up for a heroic Darkheart Thicket, everyone's geared, first few pulls go great. Tank decides to pull 3 groups at once and ignores one of the groups attack me (Mistweaver) for a good half of the fight. No one dies, but at the end I am very obviously and expectedly out of mana, so I say "drinking" and pop a squat to drink. Not even 5 seconds after I said I was drinking, the tank is pulling 2 more groups way too far away for me to get to, so they wipe. I ask why they didn't let me drink, and a few seconds later I am removed from the group.

Now, as I sit here and wait my 30 minutes because I got a "deserter" debuff, I figured I'd post and remind all the tanks out there that you should be watching your healer's mana. If their bar is empty, don't pull another group!