Situation in France
Yep, it was a mistake to leave his pistol at home; I'd have suggested bringing a 12 gauge with buckshot, too, if the officer was actually allowed to own one.
Around here, tho, if rioters had beaten a responding officer with clubs, and fired on others with shotguns, I suspect some lead would have been flying, and it it would have been bigger than birdshot. And if Pima Count Sheriff's Office were somehow outnumbered, they could have called upon the good citizenry, who (1) were probably even more heavily armed and (2) aren't really conversant with the details of deadly force policy and tend to think the test is a little more like "did he need killing?"
Fact: about 30 years ago, the city police department went on strike. Burglary rates fell. Burglars knew that with law enforcement functioning, many victims would call 911. Response would give time for escape, and officers responding would be bound by standard policies restricting use of deadly force.
Without it in operation, the citizenry would figure they had to deal with it on their own, and would answer to grand juries composed of citizens who knew they'd had to do the same thing.