I think you need showdead on in your profile settings, go to their comment history and see all the dead comments they have? That's a sign of shadowban.
When you open squirtle's profile, there are many dead comments in a row.
It's possible they are shadowbanned and the comments that are not dead (such as the one in this thread) have been aproved manually. But in that case dang already knows.
Users can vouch dead comments from the shadowbanned if they have showdead on and sometimes they'll appear for everyone like this one did. Doesn't change the fact any new comments the shadowbanned user posts will automatically go dead. I vouch a few dead comments per week usually, and around half come back.
