This is a video that was actually discussed a few threads ago. It's been out for many days, and I haven't seen anything to discredit it.
As for some of your questions:
Why can't we hear the police firing back?
Police have never said they actually shot at him. There was some talk about "engaging the suspect" at some point, but it's been made clear since then that the police just waited outside trying to be as quiet as possible before the breach, and then he was dead upon breach. The interview on 60 Minutes helps with this timeline a little.
Why can't we hear the police when they used the explosive?
Looking at the room, there's a considerable distance between the window and the door. Furthermore, the explosives happened approximately an hour after he stopped shooting. He shot for about 10-12 minutes, and police didn't breach until 72 minutes. It would not be audible in this video.
Why is the last two gunshots as loud as the shots when he was hanging out the window?
He was very close to the window when he shot himself (as seen in leaked pictures). If you listen closely (or have firearms experience), you can tell that the two shots are definitely a lower power than previous shots. He also likely wasn't "hanging out the window", but firing back from within the room to conceal his location when he was shooting with the rifles.
:twocents:
