[EUW] Thresh Grab Hitbox on Blitzcrank

Well, I was watching at a friend's stream spectating a game, when this bug happened. Thresh flashed-grab Blitzcrank but the Thresh grab touched Blitz "far away" from the normal hitbox.

Clip of the action (Sadly I had not the rest of his explanations but I can find them on the VOD (maybe), I'll try!)

If you want a translate, he says : "Oh, this Thresh flash grab! Wowowow, let's watch this action again, please. The grab looked strange. [...] The grab was strange, look at it... Okay, so here what's happened. I can explain you how Riot explained this little trick: in fact they said they had......"

What do you think? Hitbox bug or just Blitzcrank too fat sad robot? [zombie-nunu-tears]