I think the disparity around sentencing for different cases of "violent rhetoric" is going to continue to be a talking point in the media. Personally, I'm quite torn: I believe in free speech in principle but obviously you can't shout "fire" in a crowded cinema and cause a stampede without consequences.
In this particular case, even if the law was better defined, the councillor would still have not received a sentence as the jury found him not guilty despite video evidence. This is particularly interesting because it seems like a case of something like jury nullification happening in the UK.