Depending on the details I can't see from this video, and depending on if he gets proper medical care (lol), it could prove to be fatal. Warning, this paper includes medically graphic images: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7578127/
Technically, this is achieved with weapons simultaneously firing the grenade and ejecting a similarly heavy mass at a similar speed opposite the direction of fire...
here specifically, good question, he can still move legs so spine is probably mostly intact, but i'd guess there's some nasty TBI and blown eardrums or at least one
With my very poor Russian, I'm pretty sure he says "ja jebu dolbojob" mockingly in Russian (meaning "I'm a fucking dumbass"), then I think the next might be "tupa mov vaflja, ce pizda" ("this cunt is as dumb as a waffle") in Ukrainian, but I don't know.
Edit: Upon re-listening I think it actually says "tupa mavpa bljad', ce pizda" ("stupid fucking monkey, this cunt"). I like what I misheard more though :)