in a real life scenario, would the gun fire after (hopefully) being redirected?
That is certainly a possibility, while being redirected. Which is why SteveS said he prefers the technique we teach. We redirect the gun in what we feel is the safest direction (away from us, and to minimize covering bystanders).
Now once the gun has been redirected, and it has fired, in all probability the gun is now in a state of malfunction. By grasping the gun, you would generally not allow the slide to travel. This is why we are pretty big fans of creating alot of distance while accessing our own firearms.
Trainers are individuals. SteveS and I do not agree on each technique we teach, but we are open-minded enough to rough out a technique. We come from different backgrounds in our early martial arts experience, but had the same work experience. So in the end our techniques end up being very similar, because we applied those techniques almost daily in the roughest patrol district in our jurisdiction (during the "roughest" shift). It's a constant test and evaluation of a technique to determine whether a technique is retained or discarded.
Southnarc and Mike Brown are very similar in their techniques. They differ somewhat in what SteveS and I do, but in the end our philosophies are the same. You cannot "access" (Southnarc's term) your own weapon/engage your enemy until you have control of the weapon that is about to cause harm.
I wish I could compile a comprehensive list of "must see' trainers. But that would be impossible. The 3 listed above are a great place to start, and Steve and Mike are local.
There just isn't any one perfect "system". Krav is great. Gracie is great. Southnarc is great. CQT is great. But there are holes in everything. Has to be. That's the nature of what we do. Which is why I'd say a great trainer is one with real world experience, and is well-versed in different systems, and knows how to relay information to the student.