That doesn't mean they don't have the expertise. They probably weren't looking at what I had the insight on. Now they can look because insight has been shared with them. I believe they only considered the two simultaneous equations, because that is what they were told to look at. Or they did see those extra equations and dismissed them as irrelevant for some reason.

Different people have different epiphanies at different times. I am out of practice on math because I don't use it in programming much. That was nearly 3 decades ago that I was in university. Cryptography gives me a chance to use it more, but I find that a lot of concepts slipped away from me over the years. Might be an age effect. They say our peak ability to discover new math is in our 20s or at most 30s. By 40s, we are reduced to being managers and teachers. I am trying to prove to myself this is not so and I pushing 50. Worsened by being out-of-practice, unlike for example Bruce Schneier.