I'm not a lawyer, but I've been in your shoes.
- The person accusing you of passing the bus must give a signed affidavit and testify in court. If she does so and lies, it is perjury, which is a felony, and she can go to prison for that. In court, you should point this out to her during her testimony. "You know that lying in court is a crime and you can go to prison for this, right?" Also, make sure to point it out to the judge: "She's lying, your honor. This is a retaliation for [xyz]."
- If there were other witnesses (e.g. bus driver, kids), they should have been questioned / referenced.
- If so, get their testimony in court
- If not, ask the cop in court why he didn't get the accounts of other pertinent witnesses. The bus driver is very important. Also, use this as conjecture to draw the conclusion that the woman is lying (i.e. why didn't she get the license plate of the bus and give that to the cop?)
- Adamantly deny everything and be angry. If you are passive, people will assume you're lying. I believe passing a school bus is a criminal trial in most states (lawyers correct me if wrong here). That works to your advantage, because it means they have to prove BEYOND A REASONABLE DOUBT that you did it.
- Tell the judge why you believe the woman is lying. Did you cut her off or give her the finger, or what? I once cut a woman off in a parking lot and took her spot (bad, I know) and she called the cops and told them I keyed her car.