While he does see it coming, and maybe expected to get a similar kind of reaction, his reaction time is restricted by the bandages on his arms and his previous round of pain killers.

So of course, he lifts the badly sprained hand as opposed to the one with a hole in the middle, and of course it hits him right in the most tender area of his palm, causing him to drop it before his fingers even close.

He'll get to yelling at her once he's done swearing and trying to shake out the shock of pain in his hand. That's the exact opposite of what he wanted, thanks.