A lot of times people get hit by Blitzcrank Q because the hitbox is slightly bigger than the visuals, and the fist animation is very outdated. We can kill two birds with one stone by changing the model of Blitzcranks hand during his hook, to improve the visuals and make it better represent the hitbox.
So instead of having a weird closed fist go next to champions, attach to them, then come back, the hand should be _open_ like on his splash art, like he is reaching out to grab you. Then once it catches someone it can change the model to be closed on the pull back.
(sorry for bad photo job)