Zipperfish Zipperfish:
If Canadians were killed by friendly fire, I don't see any reason why that should be secret. It's a reality of war. I can't think of what military strategic use it might have to keep it secret.
The reasons you'd keep something like this secret is because there were probably details involved that could expose either ongoing operational techniques or because that information could threaten soldiers who are still in the field.
For instance, when some buttmunch reporter exposed that the USA was using Al Qaeda cell phones to hunt down and kill terrorists we lost an incredibly useful tool for finding these vermin.
Long story short, information about the military can be viewed as an algebraic expression and sometimes very critical information is exposed by very simple details.
In this case that would seem to be the case as both the US and Canadian commands agreed that this info needed to be secret.
As a for example:
If the four Canadians were operating out of uniform in an area where Canadians are supposedly not operating then you're exposing some pretty important info to the bad guys with just that.