Canada (or any westminster system) has no absolute guarantee of free speech. Parliamentary democracy is based on the principle of absolute parliamentary sovereignty. The political system is incomparable. Parliament is not even anywhere near the same thing as Congress (or vice versa). The Congress of the United States and the Congress of the individual states are completely subject to a higher law. There is nothing similar in Canadian politics. Even the Canadian constitution is another Act of Parliament, no special consideration required. That is to say, the Canadian Constitution (as expressed in the Constitution act of 1982) is such because parliament says it is so. On the other hand, the Constitution of the United States of America exists because it says it does, and Congress is subject to it and cannot change it on its own.

In order to amend the Canadian constitution, Parliament must amend it. On the other hand, Congress can become subject to changes in the constitution even without its consent, as was seen in the passage of the most recent amendment.

In the 1980s a university student decided to change the constitution against Congress's wishes and was able to do so, by getting the states to change the laws to which Congress is subject. Try doing that in Canada.