Who do you think JUDGE will believe? Driver or policeman? This is like caught using cell phone while driving....
We live in Canada.
Also, if LZ actually has "顺手刮了一下胡子", then that is a fact, maybe LZ go to court, and when that policeman arrives, ask him/her to reduce fine...
We live in a democratic country. Policeman has to provide evidence. "警察笔记" is the evidence. If is quite unlikely that policeman forgot to write down what he saw, that is a standard procedure.
"比如说会不会出庭作证" - LZ has to count on LUCK. If a policeman shows up to give evidence, that policeman collects two hours of overtime, again, the chance of NOT showing up is pretty thin. Maybe LZ can find a ticket fighter, don't count on luck.