If you had more karma, you could "vouch" for the comment. If enough people were to do so, the [flagged] status would disappear. Failing that, you could email the mods to draw their attention to unfairly flagged comments. They do have good taste, however, so they're likely to leave the comment in question [0] flagged. Unlike IRL, the system at HN is rigged against racist dog whistles. If one is ever tempted to write the sentence "This is not flamebait.", one should think more deeply.

[0] https://news.ycombinator.com/item?id=23794262