I'm expert, and a smartass?
If i had a CHL, yes, I would know EXACTLY when to, or when not to, pull it out.
"memorizing the whole damn book" or knowing the sections that pertain to deadly force isnt much of a huge task. As a matter of fact, it should be your duty as a CHL holder, to know the law.
Or, you could always live by: "When in doubt, whip it out"
I'm sure you've never given it any real consideration, because if you had, you'd know that use of force or deadly force is never black and white and that it isn't just a simple matter of memorizing statutes.
Just because the law appears to say one thing doesn't mean you won't be prosecuted involving the use of weapons - whether you actually shoot [at] someone or not. There are huge grey areas that aren't clear. That's why people hire expensive lawyers to argue these things in court when folks don't agree on what the law says.
I think the sentiment is wise; it is good to have a really clear idea of what you would do in a variety of situations. But thinking you will know exactly what to do when something actually happens is unlikely. The best thing is to ask questions, like the OP did, and get feedback from people with varied perspectives on how to handle things.
To the OP,
Liability issues and legal entanglements can far outweigh any perceived good you might have done by engaging the thieves. In situations like that it's probably best to just let the stuff go and be "a good witness". Any number of things can go wrong if you engage, including shooting someone innocent, or causing property damage that costs more to fix than what you are trying to protect, not to mention potential legal costs.
For me, it is almost a matter of fiscal responsibility to not get involved unless lives are at stake. But then that's grey too.