No-one could confuse vehicle exhaust with gun smoke.
I am sure the police outrider would recognise it for what it was, but it is reasonable to question evidence.
Your case seems to be that it is not proof. As I said, no-one here has ever claimed that it was.
Just that "there is evidence," including the evidence of witness testimonies.

Witness testimonies are universally accepted as evidence.
You make yourselves ridiculous by denying that fact.