Denying charges

My son had gotten a ticket for "driving to endanger". The problem here is that he did "peel out" of a school yard (no kids around) with 2 other "so-called friends in 2 other cars. The only person to see them was a custodian who only caught one license plate #, not my sons. He reported this to the resource officer in the school, who then contacted the owner of the plate who denied speeding and gave a reason why he is at the school. He said he was following the other driver (also involved) to pick up her sister. He gave that girls name who was questioned and stated being innocent. When they finally reached my son hours later, so-called friends giving his name...he was the "stupid' one that told the truth about clowning around and got the ticket. Is there really a case here since the only witnesses were the 2 friends "saying what they saw, and the custodian who had gotten another license #? I'm thinking the license plate he got must have been doing something wrong or why would he have taken it down? ALso my son is denying the police report which we didnt see until today and looks worse than what really happened, never signed it.
Any thoughts on this??
Thanks.

 

Driving to endanger

State of Maine
Violation 17A
Section 2413

He pleaded not guilty, not sure how to handle this next court date.
We would like the charged dropped if not lowered.

Thanks....