Right then,
I found out how Janecky did it via the most wonderful and venerable mission editing FAQ. It's on page 11, J W's post.
http://www.flashpoint1985.com/cgi-bin....;st=150
Simple really, you go into the mission.sqm and alter the side of the units you want on another side, and voila, instant insurgency (and such).
But the above-mentioned option also works of course.
Well I'm off to set some IEDs for my players.