The officers issued him an official warning after determining his actions were not racially motivated.
“I do not imply, for instance, that we should always suppress the utterance of intolerant philosophies; as long as we can counter them by rational argument and keep them in check by public opinion, suppression would certainly be unwise.” - Karl Popper
Banning certain kinds of speech doesn’t prevent the thought behind it. The speech will continue, it just won’t be where you can police it.