Of course cops are people. Highly trained people who wear body armor and are actually a part of finding the suspects.
The idea that this situation would have been safer or would have come to a more positive end because amateurs had guns is crazy balls.
Rhetoric like this just perpetuates the negative stereotypes of gun owners as out of touch cowboys that think not only that guns are the solution to problems, but that bigger and more powerful guns are.
Hell, if there was people "cowering in their homes wishing they had an AR-15 with a hi-capacity magazine" they'd be misinformed. For close quarters home defense a shotgun is going to be more effective and less likely to unintentionally hurt others in or around the home.