Good question -
In the most general of terms anytime you become formally "trained" in the martial arts there is a presumed liability as to what it is you can do as opposed to the untrained brawler or flared out citizen. This includes techniques, their applications, and what the technique may result in injury wise.
Chokes can kill a person intentionally or otherwise. For many police departments the submission choke most often taught in the academies is a formal portion of the Use of Force policy. And, in many cases, the officer cannot use the choke except under specific circumstances and ONLY if he or she has been trained under the auspice of the department in the application of said choke.
Other departments have done away with this choking technique simply because they don't want the liability as opposed to teaching and sustaining their officers' skill level in using the choke if necessary.
Joint locks are good but clearly there are some that can and will dislocate / break a joint badly once applied with sufficient force and speed. The circumstances of the confrontation will determine a great deal according to the general "what would a reasonable person most likely conclude and do" under the circumstances that were known at the time. Street fights and fighters don't often "tap out" and agree you've beat them fair and square. And if it's multiple attackers the equation changes dramatically. And if you fight back, and appear to be fighting back successfully, the escalation of violence directed against you often increases on the part of the attacker(s). So, learn well and act accordingly.
Many, if not the majority of instructors are content to teach sport applications of their art(s) and cardio-fun hybrids for the "I wanna get healthy" crowd that thinks they are learning self-defense while doing jazzercise in a martial arts dojo. Other instructors - and students - are seeking pure offensive/defensive physical training in close quarters combatives for whatever reason(s) they might have. As noted earlier, with the limited time I had with Rickson Gracie - and he with me - he asked what I wanted to learn and I told him. He taught me. I retained the knowledge, and sustained the lessons through practice. I've used those lessons and techniques on the street since and done so successfully. It didn't take me a year (bear in mind I had a way solid CQB base to work from before seeing Rickson) but only a few hours.
I recall teaching a certain private student of mine how to shoot a handgun CQB better than many cops I know and did so in roughly a day
Again, the most important quality an instructor in any art can have is the ability to transfer his knowledge and skill to a student needing specific training, or general instruction. Frankly - and I've said this before - all too often the people who need quality self defense skills and confidence are all too often those who don't have a year's dues to cough up; don't have 3 days a week, one hour a day to visit the dojo, and need the ability RIGHT NOW. These are the folks who are penalized by traditional martial arts instruction, which is first and foremost a business anymore and hence requires long term financial commitments in order for the instructor to stay in business.
Fact is, you can teach folks how to fight and fight well in a very short amount of time if that's your motivation and desire. Kelly Worden does this: Paul Vunak does this; Rich Chen does this; and I've done this for both individual and group clients / friends / comrades in arms.
As Clint Smith of Thunder Ranch says, "It ain't good, it ain't bad, it just IS."
Train on and learn what you want from the program, and maintain what it is you believe you'd most likely need / use. Learning and improving are the objectives of the serious student/teacher. Then make it all work for you
As Mushasi wrote - know as many weapons and arts as you can. In the end this knowledge shows you what you can do, should not do, and have to do if faced by opponents whose tactics, techniques, weapons, and skills you recognize from your studies.
On another note -
I like Grandpa's thought process. One, a .25 auto in the hand of a man who is willing to use it and can use it will do the job before one even knows a job is being done. Two, a very talented and wise Silat instructor once told me that the best defense he's seen is a barrage of fast and furious punches to the head. My Wing-Tsun instructor identified himself as a "head hunter" when I began training with him (old style San Francisco Bay Area martial artist of the 60s era of American Martial Arts). He loved bridging the gap through fast, articulate footwork and then blasting his opponent's skull senseless. A totally disarming looking man I was way impressed by how adroit he was / is at getting where he wanted and needed to be in order to turn one's lights off. Deception, Surprise, and Cunning are seldom taught by sports instructors...but these are traits ALWAYS taught by fighting instructors.
Rock on...
