You've found an odd edge-case. baybal2 is banned intentionally, despite the fact that most of his posts are good, and some are great. Unfortunately, the remainder aren't. The compromise is that he's banned, but users like me vouch for many of his good posts to make them visible. Here's a post from Dan about him a couple years ago: https://news.ycombinator.com/item?id=29692791. And another from 4 years ago: https://news.ycombinator.com/item?id=21195898.
I'm going to contact the moderation indeed, it's the first time I was seeing non-spam comments being shadow banned automatically.