That could well be. And in a lot of cases could be. I was just pointing out that other factors can make that difference, too. If someone just doesn't mesh well with the instructor (or, specifically, with that instructor's teaching style) they won't learn as well as they would at an otherwise equally good place with an instructor more suited to them.I can almost guarantee he is just in a better learning environment.
Same goes for interest level. What people are interested in matters for learning.
Of course, I'm not saying a crappy system with a well-suited teacher works better than a really good system with a not-so-well-suited instructor. It's just a question of how several factors can all make a difference, so we can't look at an individual case like that with much confidence.