Zilean Q

I just wanted to hear opinions on the way Zilean Q counts as agro. Zilean Q pulls agro at two points:

1. When the bomb lands on a champion
2. When the bomb explodes and damages a champion

While no one will argue with occurrence number two, I think there are a number of situations when the first is at the very least inconvenient. Namely when sieging/under turret. This makes sense and I don't really mind it unless I turn off my brain and take an extra turret shot bc of it. The one I dont particularly agree with is when the initial bomb landing affects out of combat effects (ie; mobis, ocean drake, garen regen). I think under tower it makes sense but outside of tower it doesn't. I'd like to hear other peoples feedback.