You "don't cause pain in any technique"? Really? I find that very hard to believe.
Fortunately for me, my experience is not predicated on your belief. There are more things in heaven and earth, Mr. Story, than are dreamt of in your philosophy. There may be a few people here who have trained with our folks recently enough who might be inclined comment on what I said. Tarik? Jun?
I know more than a few people who can lock me up from scalp to tooties without causing me pain. In fact, my teacher can throw me around without me being able to viscerally compute how it's even happening, despite my understanding of how it's happening. (Sometimes. I'm getting more skillful at figuring it out, but he, annoyingly, keeps getting more skillful, too. So there's that.) I, myself, didn't believe it until I first got my hands on my teacher. After that, there was no option for me but to leave Japan for Arizona to figure out how he did it. That was almost 16 years ago.
Did I say "pain doesn't happen?" Or did I say "I don't cause pain?" Very different. Perhaps we define "pain" differently or are parsing what I said in dissimilar ways.
Let's break this down to the minute particulars: Deliberately causing pain as a means to an end is very different from incidental ouchies that might occur as a result of uke struggling, Mr. Murphy stopping by for a visit, etc. Very different. I find this to be a useful question: Am I DOING the technique, or is the technique HAPPENING? If I have to rely on causing pain, I'm doing it wrong. I never want you to say "ouch." I want you to say "WTF???"