[n3rdy]

Looks like he may not have had enough variation in his replies.

If you have only 20 different tweets, its easy for them to look like a typical bot to automated filters. Even if you are posting them slowly, it wouldn't be a stretch to assume one flag would be a ratio of similar tweets.

The response criteria could be another thing raises a flag. It wouldn't be difficult for a filter to recognize someone only replying to specific key phrases.