I don't trust my hand strength enough to do anything like this. I have to take breaks bringing my grocery bags into the house. This guy's hand looks like he could crush a full beer can, so I don't see him having any problems. He probably has one of those jobs where he tightens screws with his bare fingers all day. That's a job, right? Maybe if I made my keys harder to press I'd have hands like that guy.
You really have to trust your photographer when taking a picture like this. They can't dilly dally. "Hold on. Stephen just texted me. I gotta text him back." / "Just take the freakin' picture!" You don't have time to be picky for something like this. You don't want to fall to your death just because you forgot to do duck face and had to retake the photo.