Making a mistake is not the same thing as trolling. Trolling is being willfully wrong, usually to gain some benefit (eliciting a pleasurable response, financial gain).

Showing that they were incorrect does not show they are a troll.

If LayerVault made a mistake and apologized, sure. But one look at their twitter page & their response on designer news implies no apology is forthcoming. So, they are copyright trolls and bullies. They are not only running against the spirit of the law, but also the letter of it.

Please see: http://en.wikipedia.org/wiki/Patent_troll

The term refers to entities who are in the business of enforcing patents they aren't generally even using in the marketplace. This is distinct from someone who actually thinks their work is being affected, as is the case here (even though in this case it seems to be overblown).