Acid commented before the meme was submitted. Unsubmitted memes belong to the creator's personal profile space, not a stream. Because stream moderators only hold power over their specific stream, a stream-banned user can still comment on your unsubmitted memes if they have the link.
Imgflip features a few distinct levels of moderation based on site-wide and stream-specific authority:
• Stream Moderator: Can only moderate content (such as deleting comments or editing image titles) within a specific user-created stream.
• Site Moderator: Has the authority to moderate content across all streams and can ban users from the entire website.
• Global Moderator: Possesses all the same perks and site-wide privileges as a site moderator, with the added ability to feature or unfeature images in the main "fun" stream.
You actually called him a jew which was accompanied by a meme of a black Jewish child in Jewish attire "Before" he called you a groomer. You both were banned.