Yep. The gas grenades they used were exothermic. In MANY cases they would start a fire. They were kinda expected to by authorities. It’s just how they worked. They expected to flush out the perps and then put out the small fire if necessary .then the fire starts
So if you toss one through an open window and it rolled onto hardwood you were fine. Through a closed window into heavy curtains? It would fall down behind the curtains and catch them on fire.
And I’m sure some of them just figured “if the gas doesn’t drive. Them out, I guess the resulting fire will force them out. “