Sure. You can sue them for the difference between what you paid and what the ad said. And then McDonald's army of lawyers will descend upon you and...

None of us can predict what the judge will allow into evidence. You really need your own attorney. This is not a DIY project.

As long as you are not signing or providing legal advice, I don't see any issue with you doing the filing. Ask the clerk's office to be certain.

If you don't go back, you will likely be arrested. When you go back, do not say anything to them about the subject of the investigation....

That is up to the judge/magistrate to decide.

No you have no case. They were trying to protect you. And you want to sue them?

The person you "out" can sue you. See Johnny Depp. Then a judge or jury gets to decide.

This is a general Q&A site and not a substitute for specific legal advice. No lawyer from this site is going to directly contact you. Given the...

It means he needs to speak to his attorney. There is nothing you can do for him.

How was the judge to know the info was wrong?