“Passing An Emergency Vehicle”

I was on a 4 lane divided highway, speed limit 60 kph, and I passed a cop. I was doing 65. He pulled me over, and gave me a warning, telling me I wasn't allowed to pass a cop. His lights weren't on, and he was doing exactly 60, so I passed him, like I would any other car.

Is he being a jerk, or is it foolish to pass a cop who is doing the limit?

I searched the OHTA for any mention of not being allowed to pass emergency vehicles, but couldn't find anything.

Passing a police vehicle in itself isn't illegal, it's simply the fact that you were speeding while doing so. Police will frequently exercise discretion and ignore minor speeding offences, but passing one while exceeding the limit probably isn't the best idea.