Also, if he can't keep his cool under those conditions, he has an obligation to change jobs because if he can't handle it he's just putting other people in danger.
LA Riots in 1992. Police pulled out to avoid conflict and it resulted in looting and burning for days until the National Guard showed up.
Minneapolis was burning before the police responded, not after.
Haven't seen or heard of any fireworks, which you can be sure the police would not tone down in reports (probably describing them as explosive projectiles).
It certainly isn't easy to keep your cool if things are been thrown at you, but that's the job. It's not an excuse to violently attack protesters who are not throwing things or use inappropriate methods.