If you are interested in how many over-revs you have on your motor, the type etc. you can buy an ODBII testing tool for your 997, such as the one Durametric sells for less than less than $200. It will also tell you the engine hour that the overrev took place. By the way, they are counting the number of ignitions of each spark plug in the over rev range. Bouncing off the rev limiter just briefly will always result in a couple dozen or more (perhaps 100's) of ignitions.
The Durametric tool also shows many types of engine error codes and can clear all the error codes (not the overrev counter). It also performs functions like clearing out the service indicator etc.
Having used it for a while I find it a useful but then again, as a software developer, I am into all the tech details and can not afford the 10K Porsche diag software.
It may be a good way to double check your dealers claims especially since it provides the engine hour detail letting you know when the over-rev took place. I do not think the dealer can get that detail. If the type 2 was a long time ago I can be reasoned that it was not the final or only cause of the engine failure. On the other hand it may be nasty evidence against you if it was recent.
Best of luck. Keep this thread alive as it will be noticed and it may help your situation. (Stay positive in your posts and praise them for all the effort they are making... all that BS!)
Drive right!