Speed Dropped, Prosecutor Threatened To Raise At Trial

I'm helping a friend with a ticket. He was clocked at 25Km/h over in a 50 zone. The officer reduced it and gave him 15Km/h over.

He chose option 2 and spoke to the prosecutor. The prosecutor told him that if it went to trial, he would be tried for the original 25Km/h over.

Is this correct?

I told him he should request full disclosure at least in case it's just a threat to get him to pay. He can always pay the fine up until the trial date. I would rather see him take it to trial but he doesn't want to risk the 25 over.

Thanks in advance for info

Yes, speeding tickets are routinely amended back up to the full speed at trial.