Just because it was mounted using zip ties doesn't necessarily mean it was mounted illegally. Was it still mounted on the back of the bike, under the tail light (in front of the tire), flush to the back of the bike so it was clearly visible from behind and all that? I don't think it states anywhere in the statutes how you have to fasten the plate, just that it needs to be easily visible. Now if it was hanging there all loose and shit blowing in the wind and flapping up and down I think he is screwed, but if it was secured well with zip ties just take a picture of it and show it to the judge.
Considering the fine is over $1,000, I think he is crazy if he does not fight that ticket. I cannot believe a cop actually wrote that when there were no other infractions leading up to it. Your friend didn't like flip him the bird or tell him he belongs on Super Troopers or anything like that did he? I mean, a $75 ticket for a questionable tag is one thing, more harrassment than anything, but $1,000 ticket should be reserved for only the worst of the infractions (like missing plate entirely, tucked up behind the tire where you can barely see it is even there, etc.).
Fight that shit either way man! What's $100 or $150 for a lawyer when there is so much money on the line? Even if you get the fine cut in half it is worth it, but I bet the judge has a very hard time ruling you have to pay $1000+ for a tag that was clearly visible but technically not fastened properly.
I also hope this doesn't mean the cops are going to start writing these rediculous tickets all the time for next to no reason. I was furious when I heard this law passed but I figured it would just never get enforced. This is the first I have heard of anyone getting hit with this B.S.