"Taekwon-do contains many locks (and breaks) if we study properly. Early in its development Taekwon-do incorporated elements of another Korean art, Hapkido, including many of its joint locks. However, someone deemed much of them either too long, too complicated or not instant enough so they were discarded and those that were kept centred around being quick to apply or causing a break and not just a lock. Many locking techniques can be found within the patterns" (1) I mean that statement justifies why the members you mentioned know some locks, well yes HKD and TKD share very similar principles. I think a good HKD school is one that is taught by someone who has studied mostly HKD in the first place. If their teachers as you said where Masters in TKD then I can understand their habit of passing on TKD kicks, come on, after all they been training/studying and teaching TKD for 20+ Years, easily done! So my opinion is learning from does who have studied the art longest, thus if you learn from a TKD Master, your bound to get superb TKD techniques and the same for goes to a HKD Master. Its just one of those things, and instructors should understand this and think to themselves "Was that that a TKD kick I demostrated or HKD kick?" and own up to their faults. (1) http://www.iainabernethy.com/articles/Stuart_Anslow_1.asp
There are school here that do the same thing. They advertise as being a 4th degree in Hapkido, but have never taken even one Hapkido class, they were at a few seminars and were giving a sheet of paper that said they earned a black belt. It might look good in advertising, but you will never learn Hapkido in those places. There are some people who have EARNED Master rank in both HKD and TKD, and that is tottaly different
