Why did you keep all that under your hat? Who did you contact besides Gartner? Did you tell the guy in your organization responsible for renewing their contract? Did you tell the press? Did you tell the PR department at Apple?
Do you have the documentation currently? ISTM that there are thousands of reporters looking for a story that has an "Apple angle". The allegations made in the current situation fit perfectly with your documentation and story about another past incident - and they BOTH involve Apple and Gartner.
If there is any validity to your allegations, please contact Pouge and Mossberg. Their people will get back to you. They got lots o' kids hanging out and Jonesing for a Pulitzer.
I had a web site up back then that had all the data with nice graphs. I contacted MacUser and MacWorld and it was well known on comp.sys.mac.advocacy.
At the time, no one cared. I don't have the data any more, but it wouldn't be hard to recreate it if you look up all of Gartner's estimated and actual software sales numbers from the 90's.