derioderio

Technically, the WoB was that Bloody Tan wasn't an atium misting, that's all. It's still possible that that Bloody Tan gained the ability to burn atium through Hemalurgy, which considering the state of the people he had killed and his obvious insane state, is very plausible, I think. If so, he would have had only a sliver of atium, just enough to know how to move Lessie's head to intercept the bullet. He then didn't have enough to prevent himself from being shot. Or alternatively, he chose not to dodge the bullet to his own head, in order to complete his "art".