I'm gonna go out on a limb here and suggest that there's more to the story than what's been told.
I saw a photo of the "fake RCMP police cruiser" in a Nova Scotia report on this story yesterday, and I could only conclude one of two things:
1. The RCMP police cruiser was actually a stolen vehicle, not one that was made up to look like a police cruiser.
2. The job looked so realistic that the guy had to have professional help doing it.
...or maybe the shooter actually WAS a cop?
Read up on the Killdozer. People who feel they have been affronted will sometimes go to great lengths for retribution.
Lots of planning, not what you typically see.