The guy really doesn’t look like he knows what he’s doing. The lady picks up on it and promptly nopes the fuck out of there.
Honestly he looks experienced to the point of routine. She ran off as he unscrewed the cap, which is just a protective cover. He started immediately shaking the bottom to help get access to the pull string with no hesitation, he knew exactly what was inside.
I’m doubtful. He just threw a grenade in the open with absolutely nothing in between him and the explosion to stop the shrapnel. I wouldn’t be surprised if that guy had to be rushed to the hospital after that take.
Grenades of that type (M24s) had basically no fragmentation. The warheads were thin bodied metal, and didn’t by default have a fragmentation sleeve. The effects of blast were short ranged.
The throw was shorter than I’d personally feel comfortable with if I didn’t absolutely have to be in that range, but he was likely just fine.