No, your not mate, don't worryThat's a good starting point. But was Hiagonna sensei just saying that to sound relevant? If he was able to show some of throwing, joint locking, and choking, was it standing or on the ground? Was it one of few often overlooked techniques in goju? If it's so common, can you link some video? I'm learning here and just asking questions, hopefully I'm coming off as to smarmy
Here Iain Abernethy explains that the "jump" in Pinan Godan (which is often interpreted as someone jumping a katana ) is in fact a way of preventing your opponent from spinning out of the joint lock that is being applied.
Pinan Godan Heian Godan Throw video Iain Abernethy
There are other examples (just as there are other alternate explanations for these same moves). But we know from the writings of the old masters that ground fighting was originally in there somewhere. Unfortunately it has been lost to a large degree now karate focuses mainly on block/kick/punch, so it becomes difficulty process of practically minded people like Iain, and others, trying to "reverse engineer" the information back out of the kata.