Illegal?

[MikeH]

Your cousins friend must have had a truly crap lawyer, or the knife was a prohibited type (butterfly knife, switchblade etc.) An appropriate knife in your fishing tackle would be a hard sell in court as a weapon for fighting. But... having a long fillet knife hidden on your person could cause you major problems with the law. So some common sense is needed.

I carry a multi-tool leatherman style tool which includes a 3" knife blade, I have not had any issues with police, MNR or even the US boder guards who have seen it as part of my fishing tackle.