“Could Use Some Advice”

I could use some advice on a careless driving charge I was issued after a collision, the gist of which is the following:

I was travelling on the inside lane of a 4 lane road (2 lanes each direction), which is intersected by a 2 lane minor road. At the near (to me) side of the intersection there is a crossover. As I was traveling there were vehicles in the adjacent (curbside) lane turning right. There was a vehicle at the edge of the minor street waiting to cross the intersection.

The crossing guard at the intersection suddenly interposed in front of one of the right turning cars and began crossing the street. At this point I was going approx 40-45 km/h with 2-3 car lengths until the intersection. The vehicle on the minor street proceeded into the intersection shortly after the crossing guard walked into the street. By the time I could begin stopping I was already in the intersection. The other vehicle collided with the side of my car near the back.

The police were called and an collision report started. After collecting statements from me and the other driver, the other driver was issues a charge for something like failing to yield to traffic. I was not charged. The collision was ruled no-fault.

Here's where it gets sticky. The collision report couldn't be finalized because the crossing guard left the scene of the accident shortly after it occurred. The officer had to get her contact info from the school and track her down for a statement. She says that I had to swerve to avoid her (I did not), so the next day when I met with the officer he said he had to charge me because of what she said.

The officer told me that he wrote it up as careless because neither he nor dispatch could find the correct charge at the time - which I believe is "Fail to stop at crossover". The officer told me how to contest the ticket and to get in touch with him before the court date (he gave me his cell #) so he could let the prosecutor know the more appropriate charge. So I filed a court date and intent to contest. Does it sound like a reasonable case?

Here's the other thing. I filed a while ago and got my court date, but as I had no idea about the process, I didn't know about disclosure. Of course, once I found out about it I filed for that as well, but I only have 4 weeks until court and disclosure is supposed to be done with 9 or more weeks. Any chance I'm getting disclosure before my date? Anything I can do if I don't?