I have actually been there and done that. Well not exactly the same but making the perps aware that I was armed had a magic affect on them.
I didn’t fire the gun, actually didn’t even get it completely out before they realized what I was doing. Still them knowing I had a gun was the important thing. That is why firing an attention getting shot is sometimes the right thing to do.
Sometimes it is not. That is why we use judgement.
Also was in a similar situation about 25 yrs ago in Pgh, PA.
Intervened in an assault, turned out to be an attempted kidnapping, by a feral yout on a little blonde college girl. Jumped in, unarmed, without adequately surveying the situation.
Instead of 1 perp there were six and I ended up with the back of my head split open with a brick and the perps trying to stomp and pound my brains into the pavement.
Saved the girl though, started carrying the next day and haven't stopped.