Again, you're not only speculating cells' intentions, or his mindset, but also the amount of power he was using. Thats why that really isn't a feat you can measurecell was faking the whole time. It was clear when he revealed to vegeta that he wasn't worried about the attack later. Cell never had any intention of dodging it, he was merely surprised that it was more powerful than he thought.
Besides even if we were to assume that cell couldn't dodge it, cell was heavily suppressed at that point. He wasn't even using 10% of his power. If he can arguably dodge an MFTL attack at less than 10% it is more than likely that he is MFTL at 100%