It's quite unfortunate that this situation was handled so poorly, my father was part of the K9 unit for a majority of his career and he'd be shaking his head in shame if he was here to witness this video. The officer could have used alternative methods to deter the dog instead of approaching it with his glock. It's like he completely forgot about his Tazer and Mace but that could be due to the situation previously building up before the dog and his owner showed up. Hell, the officer who instantly pulled out his gun is a huge sign that he's inexperienced. If they would've let the owner of the dog go to calm his pet down I'm sure this situation wouldn't have unfolded the way it did.
But there's something to take into account for all of us who aren't part of the Police force or like to call law enforcement 'pigs' as it were. You must remember that no matter how much training you receive in controlled environments, you're never ready for the real thing. Prepared, yes, but fully knowing how to truly asses a situation on the fly correctly while you're being filled with adrenaline and hoping that no bodily harm comes to you or your comrades? In the heat of the moment, when you're filled with fear, inexperience and have that adrenaline rush, all the training you've received easily flies itself out the window.
But nobody wants to take the time to think, we're all caught up in the moment that we only allow our initial reactions to choose for us. Both ourselves, the on lookers, and the officer who shot the dog.
Not exactly, the most that an officer may have while on duty is Kevlar. But hell, even if the dog were to chomp down on his arm he would've easily had a nice little paid vacation.