Well when you're actively shooting at the cops they don't just stand on their perimiter taking hits, they are going to do something about it. Like try to gas you out.
This ain't no Waco, despite how some desperately want it to be
I totally agree, however:
1. Tear gas deployed against a structure leading to fire seems to happen an awful lot. It may just be selection bias, but it feels like it is intentionally used in some cases as an incendiary weapon.
2. I have a strong aversion to law enforcement using fire as a weapon. Even in situations where I feel a hail of gunfire would be an appropriate response (as seems to be the case here), cops burning someone out feels wrong. Maybe my concern is because fire is indiscriminate and could easily kill innocents. Maybe it is because being burned alive scares me in a deep, animal way. Maybe it just reminds me of the George Washington quote about fire and government. Whatever the case,
if police are using tear gas to intentionally torch structures - even if they are pretty sure the only person in the structure is someone who needs killing - I think they are in the wrong.