I didn't watch it 'cos... well, I don't wanna watch a guy get shot to death. Does somebody deserve to die because they're stupid? Absolutely not. Can I understand why a police officer would shoot to kill a felon who is refusing to cooperate and seemingly reaching for a weapon? Absolutely. Could it have been handled differently? Sure.
As to whether I should be commenting without watching the video... I guess that's up for debate. If my opinion had any bearing on anything at all (the fate of the police officer for example) then obviously not. If it's just an opinion being put forward for the sake of discussion in a thread designed to encourage discussion, I reckon I'm on fairly safe ground