While in the Air Force, there were tales of some maintenance guy sitting in the cockpit of an F-100 or F-4 and pulling the ejection handles and plastering himself against the hanger's roof. I have no first hand knowledge of the truth of the tales.
I sat in many hundreds of those cockpits performing weapons systems checks, mostly on the flightline, and the first few times were daunting.
Was in the Army, but heard that basic story too. Similar, pulled on tarmac, didn't eject high enough to open shoot, etc.
In the French incident, just saw an update last night. There was a system failure, or the pilot would have been ejected too! What is SUPPOSED to happen, is (regardless of who pulls the ejection handle), rear canopy blows and back seat is out. Then front canopy and front seat is knees in the breeze. Everything worked, up to point where pilot was NOT ejected. Blown glass cut his face, but he was still flying. Bad wrong went very right, for once!