I read a post here a while back where someone mentioned one of their family members held burglar at gunpoint until the police arrived. When the police arrived, both the homeowner and burglar were secured, until the homeowner's wife identified him as her husband. Secure the scene first, then figure out the details. Sure, its a safe bet that the man in his underwear at the address of B&E call at 03:00 is the home owner, but its still a gamble...
I've seen it first hand as well. Not a shooting, but a fistfight that the police broke up, then searched both men, and put them in cuffs. The victim was later uncuffed, then got an apology and explanation.
So, I've already assumed that if I am involved in a SD shooting, the responding police will give me orders at gunpoint, secure my sidearm, search my person, and have me in cuffs pretty quickly. I don't think the banner is going to stop that.
I'll spend that $32 on something more beneficial, like half a tank of gas.