Exactly this. Like, nobody is blaming the officer for being scared upon hearing a gun-sounding noise, that's just common sense that they should be actually, but to empty the mag at... what? Without knowing what the target was? Or did he legit think that it was his car that was the threat?
That said, it's surely a tough job, especially for the pay and the danger. Which is all the more reason to train them at least up to the level of a kid going squirrel hunting?