Some people, and obviously this guy, are better off with doors ... besides providing a barrier between them and what is outside, it also keeps their appendages in.
Some people have the tendency to panic in situations like that ... which may be a normal reaction even if not a smart one. They think they can physically stop several thousand pounds from following the law of gravity ... the guy who tried to stop the Hummer from rolling is another example. I've seen this reaction many times ... and even done it myself, though never with a motor vehicle.
I would suspect even those throwing major flames at this guy have reacted similarly if they'd just think about it.
Les
PS: Yes ... the cage did not save the vehicle very well and should be much stouter IMO. It was probably a bitch to drive afterwards. But even though the guy had to duck a little, he did come away virtually uninjured.