If you don't stand up when it's relatively easy to do, you mark yourself. It'll happen again if you don't. It may anyway, but these guys aren't generally looking for hard targets. It's better in the long run, especially when the thief did it the way he did (not brandishing).
It's one thing to not go looking for trouble. It's another not to face it when it comes to you. If you don't resist, when it leaves, it's just going for lunch.. It'll be back. (Please see Washington D.C. for illustration.)
I think he did the right thing..
Much more importantly, so did the Cop! Good town.. The Cop in this story was every bit the hero the banker was, for standing with the banker..
Just an opinion.. Worth what you paid..