"Don't do the crime if you can't pay the fine!"
I'm just kidding. Yeah, the whole "international" aspect of it makes it more difficult. I can almost guarantee you though that the cop wrote it as "negligent" because you are from Canada. He figured you'd be far less likely to contest it and just pay the fine (more $$$$ for their coffers.)
Tough call. I'd still fight it myself, even without a lawyer. I'd like to know how it was determined to be "negligent driving" as opposed to just a speeding ticket.
But consider, if you contest it, with or without a lawyer, here are the possible outcomes:
1.) Gets tossed out on a technicality - you win
2.) State doesn't prove it was negligent driving - you win, even if you were speeding (the judge can't just change it a speeding ticket. The state either has to prove you were negligent driving or the case gets dropped, those are the only two outcomes.)
3.) The judge finds you were negligent, but reduces the fee anyway
4.) The judge finds against you, you pay the full fee and court costs.
5.) With a lawyer, you'll pay them money too, but it is highly likely you will win the case.
For mitigation, there are only two outcomes:
1.) You pay the full fine (not usually the case)
2.) You'll pay a reduced fine, but it would still be negligent driving.
Remember, mitigation is an admission of guilt, and basically "throwing yourself on the mercy of the court."
Again, I'm no expert on how this affects your driving record in Canada and your insurance rates. It might not be worth it in the end.
Good luck!