Yep, there's nothing wrong with him firing 3 shots. Check out some videos on YouTube and you'll rarely see less than that fired with some instances of dozens being fired by multiple police. It's about stopping the threat immediately and sometimes just one shot won't do it.If he'd only fired one shot and he or a fellow Police officer were stabbed and received serious injuries, I daresay the Police would have been extensively questioned and hung out to dry in relation to why they didn't shoot to eliminate the threat, as they're trained to do.
This case is full of politics and it makes me sick to my stomach.