Wlad shouldn't have been caught with that shot and probably could have absorbed it anyway, but i think it was smart if went down on purpose. (and he might have) Otherwise he would have been caught up in the ropes in a bad situation.
he was already falling before he got to the ropes, though. he went down on purpose, but really had no choice in the matter. That Lewis-Tua clip is hella funny - even more so considering that the sequence came well after the point where Goossen claimed Tua broke (or ate) his ribs.