I can't think of any way to create some of that footage but with a drone. Much, if not most was from handheld steadycams and zooming from fixed cameras.
Avata? I don't know... I doubt it. More likely a micro cinewhoop at <100-150g, so if anything happened injury would be minor to none.
I have a cinelog 30 One is analog Its Kinda like flying with a 70's color tv for eyes lol BUT they take a beating. They are great in angle mode so as long as you get used to that you would LOVE it! The DJI equiped (Air unit) ones are expensive as is any Digital VTX equiped drone. SO I always recommend learning on the analog IF you can stand it long enough to get used to it (not Long). A lot of production guys use these due to the weight ( 240 grams with a 4s and go-pro mounted) and their ease of repair. You won't see anywhere near DJI flight times with these - I get a little over 5 min with a 4s. take it over 250g with a bigger Batt and you can get 13 or so min. (6s)
Highly doubt an Avata, as Avatas typically aren't used by FPV pros. Probably a small, custom-built cinewhoop? I'm very curious what camera they might have used as the footage looks too clean to be a GoPro or DJI Air Unit in such low light. I guess they could run it through Topaz, but even then the level of detail is surprising to me. Maybe an Insta360 Ace Pro? Anyway, I'm curious if the crowd had to sign some sort of liability waiver. I would think the insurance for a drone operator in there would be expensive and complicated.