@Alan Smithee The reason most are unsuccesful in locks etc is they do not understand fulcrum points, and if you come up against someone who is very good at them, the 1st you will know about it, is when the immense pressure is put on the relevant part of the body. Someone very good at locks, throws, takedowns etc knows how to get into a position, or manipulate their opponent into a favouarable position. The fulcrum point is the point at which there is no return, knowing where this point is of a technique becomes 2nd nature, you could compare it to a competant adult deciding if they can cross the road safely before the approaching vehicle reaches them.
Before I go any further, yes I used to train in Hapkido, I attained 3rd Dan (I still practise a lot of the techniques and blend them in with my current and previous arts), it is hinted that you did train Aikido for 4 years, so you would have been a novice, and had a vague understanding of its techniques, and this is evident in your comment about the teacher trying to apply a lock, and you found it embarressing because you stopped him from applying it. The reason techniques are applied with a compliance in class is, A: the attacker can feel what its like when the technique is applied correctly, B: the receiver can feel what its like when the technique is applied correctly, only then can the student start to understand bio mechanics and fulcrum points, then you can start resistance training.
Even a novice at locks etc will know, if you are trying to apply a wrist lock for example, and its not happening because your opponent has put strength/tension in the wrist, their mind is in their wrist, so revert to a good old smack in the face, throat, plums, etc. It amazes me why people think, someone who practices an art form, that uses a lot of locks etc, are one dimensional fighters. I am in the US, september this year, if you would like a demonstration/play/spar or fulcrum points explained, I would be happy to oblige, or of course if you are in the UK, near Bath, you are welcome to come and have a play.