Probably worth to block that person then. Look for pointers of troll accounts.

• New, a few weeks or less, for example.
• Suddenly changed tone of comments (may have been hacked)
• Writes emotionally fueled posts/comments, especially ragebait; the posts support persecution or question vulnerable groups needing support, and so on.
• Upvotes ragebait.
• Check for specific terms or phrases that seem copypasted.
• Check their mod log