I thought calling them "silencers" was the Karen term. I can't keep up with the kewl kids sometimes.
Hard to tell anything from that video. The article states he was "leaving", but the perp is moving around erratically and that he's moving towards the door at that moment does not mean he's "leaving" at all. That's an assumption. For all we know he's going to turn around and ventilate everyone. If it can be proven he's leaving, the shooter can be charged with murder. If he finished him off the shooter can be charged with murder. The fact it wasn't a real gun is irrelevant.
The money the guy stole is physical evidence. He was stupid to take it and give it back to the victims. It's better to leave him with the bloody, stolen money for the police to find on the perp.
I think he did the right thing leaving. It's easier to say nothing if you're not there. Leave and lawyer up with the best criminal defense lawyer you can afford, and make it as hard as possible for a Woke DA to create a case. You can always claim you were scared and in shock and ran, and then listened to the advice of your lawyer (who I'm sure will advise not to talk to the police and to make it as hard as possible for the DA to make a case).
It's isn't "Fight or Flight", it's fight then flight.