Ruggles has a problem but it is not yours; to start with the agency should refund any fees you paid. They are legally responsible for anything Ruggles did. As far as reporting a DUI probably too much time has elapsed as certainly by now Ruggles is sober (one hopes). Now if he was a bout to perform a rude (sexual?) act for children with balloons, you could get him for annoying the children at least. Call the cops and tell them your story.
See the local court facilitator and file a small claims action against the agency who sent the clown. Lawyers are not allowed in small claims and the judge will listen to your story. The mere filing of the action may get you a refund.
This sounds like it should be in a film with Billy Bob Thornton. You can sue the agency and Ruggles in small claims court for up to $7,000. The Agency is almost certainly vicarioulsy liable even if they argue that he is an independent contractor. You might also consider reporting this to a local news agency eg Fox News who I am sure would love to go undercover and expose the children's party clown industry. Also if Ruggles is going through a tough divorce, you might end up being a character witness for his wife. Lastly, check to see if Ruggles is certified by the California Board of Clowns, Jugglers and Magician's and file a complaint to revoke his license.