I have no idea what when on, but given the facts as presented in that article, this is possible:

1. Papers publish an article about a professor.

2. Wikipedia repeats was is said in the article, and cites the article as proof.

3. archive.org and others makes copies of the article (perhaps Wikipedia starts taking copied of things it cites - which would be _really_ nice.)

4. Professor notices article and threatens to sue.

5. The papers decides the article can't be defended and so takes it down. If this is what happened copies of the article still appearing on the net doesn't alter the fact the papers acknowledged the article was false and defamatory.

If at this point the paper published an apology acknowledging the article is in error then Wikipedia then IMO Wikipedia doesn't have an ethical leg to stand on.

If they didn't publish an apology didn't this is probably the way it had to happen. They only way I'd change things is I wouldn't not be awarding the professor any damages - if I was the judge I would be saying "it's your own fault for not demanding an apology acknowledging the article was false from the paper".

As it is, Wikipedia left us to drawn our own conclusions from the link disappearing. As I frequent Wikipedia user I find myself in this position all the time and think that's perfectly reasonable, but I can see how the professor and the judge might see things differently.