Looks like four of those six shots hit him, but had comparatively little chance of killing him on the spot. However, I have a hard time believing that after 4 shots, he'd still be putting up resistance. It would seem that the officer first went for body shots, but hit way to the left, then (thinking it didn't work, as it is sometimes the case), went for the head instead. Perhaps he was stressed by being assaulted (a fair assumption) and he acted too fast to notice the guy was surrendering. Those situations happen fast, if there indeed was an assault (as he claims), then I could see anyone doing this. He'd have to pause to readjust his aim, so he still shouldn't have fired the two last shots, though. While it's a general rule with guns that you always shot to kill, a police officer should keep his eyes out for the signs of surrender.
Still, not grappling with a cop is common sense, especially if the violation was minor jaywalking. Though if it was the cop who grappled the guy first, then it'd be a much worse case. They're not supposed to do that in first place, especially if we're talking jaywalking.
However, that matters relatively little in light of all that happened. It could have ended with the case being investigated, the cop punished according to what exactly did he do, and that'd be the end of it. Instead, the PD chose to suppress the information people have full rights to, equivocate and muddle the case, as well as act like they were already 100% certain who was guilty. That was the real problem here, just how exactly the first shooting happened is somewhat irrelevant compared to things they've done later.
