Thanks a ton for all the great responses. I now see that this was extremely serious and maintenance action must be taken. I will refuse to fly until maintenance is performed. Would it be too much to at some point ask to speak directly to a maintenance person responsible for the helicopter? I think I would like to hear directly from maintenance as the final step before I fly this helicopter again.
I called the school and the person who answered said that it is the instructor's responsibility to report it. I told them I want to talk to the owner/chief instructor/maintenance/etc directly with the full story. Ultimately we agreed that they will call me back.
"lelebebbel" made a good point - should I get the instructor's number directly and talk to him so that he has the opportunity to report it. It has been going through my mind that while safety is number #1, I would hate to see a new instructor go because he made a mistake(surprising a non-primary student at 250 agl on final)... Telling him what I am going to do would probably be the right thing. It is highly likely that he had no intention to report it on his own, when I called, the person I spoke to(spoke to at night the day after the day of the overspeed) happened to be one of the main instructors at the school. He said he heard nothing of an overspeed. I believe he actually flew the incident helicopter right after me and the incident instructor had contact with him (they spoke to eachother).
I will do my best to get this worked out quick - I won't be flying for about a week, but I am concerned for the others who will unknowingly be flying this R22.
So next step - get the incident instructor's number and let him know my plans and my concern for his job? Give him a day to report it. Call the school the day after and find out whats up. Monitor maintenance progression. Talk to maintenance people before I fly?
Good plan?
Thank you again to everybody. You guys are extremely helpful.
P.S. - Is there a way to view the R22 maintenance manual online at no charge?