As other users have pointed out, to flag a comment you have to click on 'link' to go to the comment's item page [1]. I don't know why PG designed it this way but have always assumed it was a speed bump to reduce impulsive flagging, since flags are more powerful than downvotes.
We never remove flagging privileges because of just one flag. The concept of a mistake is all too familiar over here.
We never remove flagging privileges because of just one flag. The concept of a mistake is all too familiar over here.
1. https://hn.algolia.com/?q=author%3Adang+flag+link#!/comment/...