Even if he ducked and put his arms to cover his face it would still be a penalty. I doubt anybody would just stand there and take it smack in the face unless they had zero time to see it coming, it's just instinct to protect yourself.
The law is quite frankly stupid that you're expected to take a 60mph shot to the face (that's not even on target) yet still get awarded a penalty against you.
I guarantee you now that if Pogba did drop to the floor to avoid the shot that Neville would be calling him a coward and a disgrace. If it was Rashford though he'd be running down there to kiss him better