Tanking can be a difficult job on many fights until you get used to them, and if you're the sort of person who makes a good raid leader, you're also going to be pretty well aware when it *is* the healers' fault and when it's your own fault. Combat logs, meters, death logs and generally knowing "ok, that person shouldn't be spamming Renew on me" versus "whoops, I forgot to save rage for spell reflect" all help. Of course, if your tanks and healers are the honest types who own up when something goes wrong and it's actually their fault, that helps a lot too.

My personal perspective on raid leading which I didn't specifically mention in the column is that of tank and leader, so I guess I'm a little biased. Sure, it's hard to see things at times due to a big monster in your face, but that's really not so much of an issue for tier 6 and beyond. A lot of the time you don't even *need* to see things in the game if you have decent enough addons set up. As a druid I always had a full grid which also showed me things like low mana, range, certain fight-specific debuffs etc; who cares if all you can see is Bloodboil's face when you can see the Bloodboil debuffs light up and know exactly who's failing to move? That plus boss timers and paying attention to yells etc, and you don't necessarily need a backseat view to lead well.

The only times it can become an issue is on a tank-sensitive encounter when you're learning, and you really are concentrating hard on your job, leading to neglecting the raid a little. But the same can easily be said of a healing-sensitive encounter or DPS check, and ideally you have officers or fellow raid leaders of different classes who can help out if you really aren't in a position to lead something yourself.