This is just pure speculation, but I think the firmware on the camera refuses to take pictures when its GPS detects it to be in a restricted area. That’s how higher-end drones work. At the same spot where I detected my interference, a DJI drone would refuse to take off. Drone no-fly areas are well documented (and advertisef), though, so it was easy to check against those.
But surely a 15 year old Canon don’t have a GPS on it? I just can’t think of what technology they could use to detect someone taking a picture in order to interfere with it other than camera surveillance and some sort of an AI system to detect cameras. I’m not doubting you, just curious about how it could possibly work and especially how to evade it.
The Canon didn’t. That’s where my assumption of a green laser came in. When I aimed the camera directly at the embassy, I got a white screen; when I aimed it a little to the side, I saw a green dot on the screen. This is a bit of a stretch, though. It could have been an optical artifact, with the sun behind me, and me wearing polarized glasses.
