I had a friend who asked the police officer why he was getting a ticket while others were doing the same thing. The cop told him he was Moe. My friend gave him a funny look so he explained "eeny, meeny, miney, moe"
IMO the OP is going to be screwed by appearing in court. Municipal Court is just a revenue enhancement device. He will be found guilty, charged the fine printed on the ticket plus court costs. The only way to half win is to cop a plea to a lower offense to avoid points and/or pay a lesser fine. If you are on your own, good luck with that. Pros love to beat up on amateurs because it's easy. After the court date sign up for AAA driving school to offset the points. This works once every three years & qualifies for an insurance discount.
Most likely the law is not on your side and the judge is busy so won't give anything you say much notice. However, if you are already headed to the hearing, then you might still have a chance. Here in Texas, what I have experienced is that if you choose a court hearing instead of just paying the ticket and the cop who wrote the ticket can't show up to testify, then they just throw it out in a screening procedure before the hearing. Basically you show up at a designated time with a bunch of other people and a clerk runs through a list and simply tells you to go home if the cop is not available. In the case where the cop is available, then you immediately ask the judge for deferred adjudication (don't waste the judge's time with some kind of defense). If you don't have a recent ticket (1 year?) and the ticket is nothing egregious (such as not using a turn indicator), then the judge probably will agree and if you don't get another ticket within 6 months then the ticket is dismissed. No fine, no record. YMMV.
You are right, of course, in most jurisdictions. I think the OP got his ticket in Queens, NYC, where instead of going before a real judge in a real court with real rules of evidence, you get a DMV hearing officer called an administrative law judge. There is no presumption of innocence, no burden of proof beyond a reasonable doubt, no impartiality, no mercy, no plea-bargaining, and no chance of prevailing.
While I fully agree that the signal is necessary and polite, I never feel safe making the left turn in front of anyone signaling the right turn. Blame it on experience. Before even learning to drive, I noticed dad occasionally and absentmindedly flipping on his signal, and just leaving it on for a while. And this was separate from the broken self-canceling function on one car. Then noticed that some other drivers will signal several intersections early, confusing others waiting to pull out from prior intersections. If I trusted those signals, I'd already be dead several times over.
Oh my god, I just looked at all the Google Earth stuff and I'd plead not guilty because all the road markings are on the wrong side of the road. That is dangerous!!
It only looks that way because you viewed it from a North American web server from your vantage point in Australia. Without using an OA Router (Orientation Adjusting) in between, you end up with everything flipped when the IP packets go over the equator. Next time use a local server or an OA router. Tom