He seems like a pretty honest guy, so I like my chances, even though, with his fastest times (and only sub-2:10s) coming at Boston, he's not exactly impartial. I know he's had discussions on the topic with others (including Derek Clayton, who was disdainful of times recorded at Boston).
I didn't just "try" to give "an example," as you stated. In fact, I think I accounted for every sub-2:10 marathoner in U.S. history, although I didn't bother naming guys like KK and Hall who never ran Boston. (Jerry Lawson may have run Boston at some point, after his peak. I'm not sure.)
As to whether Boston on a windless day is faster than Chicago on a windless day, I take no position on that. That's not what determines whether a course is aided. In the case of Boston, the course, which is not only point-to-point but is also significantly downhill, will be faster than a loop course under certain conditions, including the conditions that existed in '75, '78, '79, '83, and '94. The same is true of a number of point-to-point courses that have no net elevation loss whatsoever, such as the old Mardi Gras marathon, which was just a flat, straight run across a very long bridge. When there was a prevailing headwind, the times were much slower than they would have been on relatively fast record-quality courses. But when there was a prevailing tailwind, the times were absurdly fast. It was an aided course.
As for world records at Boston, of course there haven't been any set in recent decades. Under modern standards, there can't be any set at Boston. Joanie, however, did run three minutes faster than the world record at Boston in '83. And DeCastella ran faster at Boston in '86 than he did when he set his world record at Fukuoka in '81.