The War Measures Act was invoked in October 1970, replaced with the Public Order act in November 1970, which expired in April 1971.
The fed-created bombing attempt was in 1974. Unless the RCMP has a time machine, I don't think the invocation of the WMA or the POA can be blamed on Robert Samson.
> They should certainly not be able to avoid prosecutions because "woops we decided that, on that particular day we'll just ignore the constitution".
The US has invoked martial law 68 times in its history, 29 of them for a labour[1] dispute (The WMA has only been invoked three times, and the Emergencies act, which references the trucker case has only been involved once).
The mechanism for just deciding to ignore the constitution is very similar in both countries[2], but one of them has invoked it a lot more frequently. And, as mentioned a few posts above, government repression doesn't even need any invocation of such acts.
[1] With that frequency, it should be pretty clear as to who the government sees as its real enemy.
[2] In the US, the 2007 National Defense Authorization act even gave this power directly, and unilaterally, to the President, but it did get overturned in 2008. Now, it's largely in the unilateral hands of state governors.
