I don't understand Russian but I didn't get a feeling that there was an "you okay?" in there. They started pissing themselves laughing before he hit the top of his trajectory and kept going right through his crumpled landing.
Either they've done this before and come to the conclusion that nothing serious can go wrong or Russians have had the doubt and remorse bits of their brain removed.
The fact that they kept laughing when it's very clear that the guy is not feeling ok is all you need to know. I have seen drunk people come back to reality as soon as something fucked up happens in front of them.