There were no rules broken. Actually they selectively ignore the rule against racism as long as it is aligned with alt-right, and not just the pol board now.
3. You will not post any of the following outside of /b/:
b. Racism
https://www.vice.com/en/article/the-man-who-helped-turn-4cha...
They selectively censor any opposing views that rile them too hard or they can't easily refute, so it is not equivalent to bathroom scribbles.
Recent example just found today (not my post).