Groklaw has turned up an interesting gem from the Wayback Machine — a blog post by former Sun CEO Jonathan Schwartz publicly congratulating Google for using Java to build their then-new Android platform.

I just wanted to add my voice to the chorus of others from Sun in offering my heartfelt congratulations to Google on the announcement of their new Java/Linux phone platform, Android. Congratulations!

I’d also like Sun to be the first platform software company to commit a complete developer environment around the platform… We’ve obviously done a ton of work to support developers on all Java based platforms, and we’re pleased to add Google’s Android to the list.

Whoops … just one problem. Oracle bought Sun, Schwartz resigned, and then they sued Google for billions over patent violation. This embarrassing little blog post has been cleaned up by Oracle, but still survives thanks to the Wayback Machine.

Groklaw claims that this may actually have a bearing on the case: if you give someone the OK to use your IP, you can’t later turn around and sue them. It’s called “estoppel”.