Towing Issues: Contesting a towing in Massachusetts - driveway violation, sworn testimony, state of massachusetts

Question
Hello - my car was recently towed from a street in Boston because it was supposedly blocking a driveway.  However, when I parked it, I visually sighted down the edge of the driveway to verify that my car was NOT blocking the driveway, and it was still towed.  Does the rear (or front) bumper of a car legally have to be a certain distance from the edge of a driveway in the state of Massachusetts?  If not, or if it is not defined, do I have a reasonable chance of recovering the towing fee and violation in court?

In general, what happens in court when it is the car owner's word against the word of the parking officer who issued the ticket?  Seems to me that the "innocent until proven guilty" rule breaks down here.  While I have no proof that my car was not blocking a driveway, the city of Boston doesn't have any proof either, other than what the parking officer claims to have seen.

Answer
The parking officer may have photos, witnesses or statement of the parking violation. In court you need a respectful, intelligent and well prepared and documented case to present to the judge. Hearsay or word of mouth will get you nowhere and unfortunately if that is all you have, in most cases, the judge will favor the officer's sworn testimony. Wish I could get better insight but that's the way it is.