How was Motobe faster than Musashi? He didn't even get his blade out half way before getting rocked.
Bottle was already in Motobe's hand, and presumably he made the first move (half the time we see Musashi swinging it's in reaction to someone else charging towards him, not already being in his face.) Not to mention Musashi had to fully stand up it seems to draw it effectively, on top of the sword being at his side and not even holding the sheath, and from a sitting position, which he's not normally doing when he draws. When you see the cigarette hit Motobe as well, he's already in motion, so Musashi had to fling it (he does this with his left hand mind you) then pick up the blade with his left hand again, then stand, then draw. Motobe has already skipped those first 4 steps and only has to hit him.
In basically any other scenario Motobe would've gotten rocked and I think he knew this, so he set up the perfect surprise attack on him by giving him the cigarette.