> How is it still posting?

Banned accounts show up as [dead] as soon as they post, so most users don't see those comments, only those with showdead enabled. Commonly referred to as "shadowbanned" but usually operators also don't tell shadowbanned users they've been shadowbanned.

Looking at the posts, there are many formatting differences added across the comments. Either the account owner are posting the comments themselves, or they are manually modifying the bot script to add mistakes over time.