The issue is not the alleged legal violation but the excessive force used.
Because generally speaking, it’s not okay for agents of the state to turn citizens into a fireball for misdemeanors.
Then there is also the excessive collateral damage to property and the danger to the public itself caused by over-zealous actions of law enforcement.
What we have is an accidental burning. As it has been described, it seems the officer was about at risk as much as the motorcyclist.
Bad things happen. Not everything is planned or certain. The judgement of the officer can be questioned. It is hard to see how he can be convicted of intentionally causing the fire.
We do not know if excessive force was used.
Outlaw motocyclists routinely outrun police and get away. That is why they feel they can flout the law.