You know, people missuse that excuse so many times. Freedom of speech does NOT mean that you can spout off hate speech and encourage others to take up arms/react with hate/incite violence/libel/whatever. There is still responsibility attached to those rights that people like to conveniently forget or just plain ignore.
Your argument about his words not directly inciting violence? He may not have MEANT for it to happen, but when it says in the song that the singer (subject) recognizes the Canadian colours and how much he hates them, well, that's pretty much cut and dried as far as I am concerned.
I really don't care if he's got another song talking about a guy who joined the military and sorted himself out.
Seriously, stop being so apologist! The guy wrote a song that has the serious possibility of becoming an anthem for those who would wish to do us harm and pretty much copies all the Taliban music video propaganda that they send out. No wonder people are pissed to find out that the government is funding this.
If he's going to be anti-war, then maybe he should be writing songs against NATO and governments, not the people on the ground that are trying to make a difference.