For all we know, the cops were firing shots at him from the time he fled the scene when he was first pulled over, until he crashed. The instant he crashed the cops at the blockade likely started firing, especially since he ‘hit’ one of them. I haven’t gotten to watch the full video yet, so my opinion is based on the short video, so far.
Once he fled the scene at that intersection where he sat for several minutes (and who knows, they might have been firing at him there, which is why he fled), he was doomed.