This is coming out of a thread in the forums that some might find interesting. You might also have fun answering this one or speculating on this one. The answers will change depending on legal jurisdiction but the principles used in the decisions will be the same in all common law jurisdictions and the same principles in all civil code jurisdictions. The only correct answer is the one you can justify using those principles.
This case is converted to an Aikido situation from one for which I had to write a decision in a Tort class about 23 years ago. The original true case was in a sport fitness chain in a common law jurisdiction.
You grade a student to second degree on your responsibility as a Shidoin. The Nidan student has their own dojo in another city. After the grading, the Nidan goes and teaches a variant of Kokyu Nage which could be a little dangerous for anyone who does not know know Ukemi. The Nidan learned this technique at a seminar you gave and it you even allowed the Nidan to use it during his/her grading.
The Nidan did show the Kokyu Nage to his/her students back home and they learned to do it quite well and it was safely practiced in his/her dojo for some time.
A couple years later, the Nidan is teaching class and shows this Kokyu Nage during class since it has become one of the dojo's favourite techniques since it is simple, elegant, causes nice soft but large Ukemi, and it is "flashy". A beginner student is in the class and is taking Ukemi for the Nidan instructor. Now, if the technique is done correctly, the result is generally safe for anyone but the beginner resisted strongly against the technique and when the Nidan overcame the resistance with more Kokyu, the beginner over-rotated and landed on the back of his head. With a loud snap, the neck was fractured. The beginner student ended up with a fractured spine that lead to bipedal paralysis, loss of job, and possibly even loss of family due to divorce caused by stress on the wife and kids.
A lawsuit is brought forward by the beginner. It has named you as one of the defendants. While the Nidan probably did learn the Kokyu Nage from you at that seminar years ago, you are not the only one who shows this Kokyu Nage. It is a standard technique within your Ryu.
These are the facts of the case. The question is, do you have any exposure in this lawsuit? If you do have exposure, what do you think may be the possible level of exposure? How many dollars?
This type of thing depends on the ability of the plaintiffs lawyer to tie you into the chain of responsibility. Did you in any way "certify" that this students was "competent" in that technique? Of course, the fact that you graded him to Nidan puts your name on him and connects you. But the fact is that you may have given him that rank but that does not mean that you have any direct responsibility to supervise his teaching. Most dojos are really independent entities from that standpoint. Did anyone grant him any teacher certification i.e. fukushidoin? That would tie them into the chain of responsibility.
Basically, the plaintiff's lawyer is going to try to say that you taught this Nidan fellow a technique that is a dangerous technique and that you are negligent for teaching such a technique to someone over whom you have insufficient supervision to make sure that the Nidan is competent to teach the technique in question. Negligence is the basis for tying you, and even the organization into the law suit, I believe.
Unfortunately, the instructor in question is almost certainly hosed... I can't see any mitigating factors such as some irresponsible action on the part of the student. The instructor is expected top be able to control his technique.
The defense for any parties such as the teacher of the Nidan instructor or their organization, if named in the suit, is to demonstrate that the technique in question is a normal part of training in your style, that thousands of people (the more the better) do this technique all the time with no injury and that it isn't negligent at all to teach the technique because there is no reasonable expectation that an injury would occur.
Basically, the defense is to distance oneself from the instructor, claim that his execution of said technique on a beginning student was irresponsible and therefore negligent.
This of course poses an ethical dilemma... To the extent that you support your student and stand behind your ranking of his competency to teach, you are also putting yourself in the chain of responsibility. If you maintain that he acted irresponsibly, you are then calling into question whether your promotion of this person was negligent... the question being why did you and / or your organization allow an irresponsible person to teach?
The only way I see that you keep yourself completely out of the chain is to maintain that the Nidan in this instance acted negligently but that you had no reason, based on past history, to have seen any previous pattern of behavior that would have caused concern. You better hope that there aren't other injuries that the plaintiff's lawyers can come up with that they could maintain indicated a pattern of negligent behavior. Because then, you as his teacher and the organization which provides the authority for the ranking could be considered negligent if you failed to notice this pattern and act on it.
So the only way to escape the chain of responsibility here is to hang the Nidan out to dry. In my opinion, considering the severity of the injury, the Nidan is going to pay (hopefully he has insurance), you are going to pay, and the organization may well have to pay. That would certainly be the goal of the plaintiff's lawyers. I would expect the insurance companies to settle out of court for some figure in the millions. No way they'd go to trial over this one unless you willing to go along with the total destruction of the Nidan involved.
Of course I am not a lawyer but I have had some training in this area via my law enforcement training. Cops run into this all the time. When they get sued for excessive force, the number one way the plaintiff's lawyers can tie the department into the suit is by negligence due to failure to train. If they have done training, then they will try to say the training was inadequate or that the techniques used were excessive. Normally, on a big law suit, the department will attempt to hang the officer out to dry by saying that he violated policy and was therefore only individually negligent. Then the plaintiff's lawyers go looking for the previous pattern's of negligent behavior that should have shown that the officer was a loose cannon and therefore the department was in fact negligent by allowing him to be in the street doing his job.
The big bucks come from tying the department into the law suit so that's the game. The poor officer is in the middle... no one much cares about him.