Yes, although I was originally onboard with Stipp, I think testimony of the form "I know what I heard. I've been around guns. Those were gunshots" can now, pretty much, be put aside. (I'm guessing even the good Dr. Stipp may be inclined to agree by now.) In the heat of the night, it would be easy to confuse the two, so I don't mean to insult the witnesses. In fact, bravo to the witnesses; it's not an easy thing to appear before the world as they have done.
I am not claiming the two kinds of loud bangs are identical in sound. They may be quite distinct, once the listener, scores of meters away, is primed to notice the difference.