You keep leaving out the part about him moving over to physically stop the officer as the officer is engaged with a rioter.
It appears he started assaulting the officer, which led to him getting sprayed.
ICE has a habit, and a history, of assaulting women. In fact, that is exactly what they were doing today until Alex Pretti, an innocent bystander who was only filming, chose to step between them and their chosen prey - a brave and noble action which, sadly, cost him his life.