spell shield jungle

I use to play pantheon jungle a lot more after they changed drag to be such a slow attacker (obvious block reasons). However, after they changed it to a spell it made sense to take a free attack with Nocturne's spell shield, but it raised a question that I haven't thought about and haven't seen to know the answer to....

Since spell shield spells (nocturne's and sivir's) block dragon attacks, I'm assuming that means Banshee's Veil will also block the attack, is this true it does this? If it does, did riot plan this so dragon would pop it if someone agros drag, or if it doesn't, why not? It would make sense this would logically work.

TL;DR ....maybe the whole team should balance agro with those B.V.'s....?