[Daugherty16]

First off, you and GF drove off into the sunset, so all was well. Nice job on the situational awareness - noticing the clothes and all. But i'm curious if your first reaction was to assess him as A) a direct threat to your GF or B) just generally that he might rob the joint and indirectly (or perhaps directly) threaten her in the process. To me, that assessment dictates how you act. Seems like you initially thought A, then when he followed her out it became B.

A bank is a pretty public place, may have a guard on duty, and generally there is always somebody going in or coming out - one of the reasons a successful take-over style robbery is so difficult. I still think staying out, listening and watching, was your best bet. If you had walked in, and walked in on a robbery, could you have made your GF any safer? Most bank robbers, unless they panic, don't shoot up the bank. Walking in might have caused him to panic and placed her in greater danger. Then again, it would take some serious self-control to stay outside if you thought a robbery was going down (because she might be in real danger).

It's all hypothetical. Until it's real. Glad it all turned out ok.

Suppose that instead of a bank, where the guessed intent of the hood is to rob the place, he had followed her into a parking garage where you just dropped her off to retrieve her car. She disappears into shadows, then he follows. Would you make the same decisions and react the same way? I think not.

The garage is much less public, poorly lit, and without the cash/vault, his perceived evil intent would be aimed at her person, not at robbing a teller. (I'm assuming you wouldn't think he was there to pick up his own car). In that event, i would immediately exit my vehicle and get after her at high speed - or better yet, drive the car in. If you're wrong about him, you and GF can laugh it off later. But if you're right, you don't want her to encounter the dude alone even if she is carrying. All manner of unspeakable things might happen if you're too slow, or he might just be bumming a cigarette from a pretty girl.

And therein lies the rub. You can't live oblivious to the things around you, but you almost never have enough information, especially if the scenario is unfolding around you in realtime, so you have to assess what you can and make quick decisions.

You sound like someone who is, or will be, a good sheepdog. Welcome to the club, and definitely get that CCW. Study tactics. Get advanced training. TFL is an excellent source of (usually) very good debate on real or hypothetical situations, but there's no substitute for that brain you already have.