If the officer thought the guy was going for his gun, what should he have done? If you were the officer and thought he was going for his gun, what would you have done?
I've already said what should/could of happened in that scenario (I'm sure they receive training on this type of event, and Yanez didn't follow protocol or he wouldn't have been dismissed would he?).
If he was in fear for his life, radio for assistance, put yourself and your partner in safety, monitor the movements of the car from a distance while having your firearm drawn and ready (just in case), wait for backup. Everyone lives.........