It's not really ambulance chasing if all he's after is a partial refund.

From the article:

As for Lehman, he wants some of the $20,000 his company pays Heroku each month returned. “We deserve some sort of refund here,” he says.

EDIT: I re-read the article, and it's not even clear that Rap Genius is part of this. Looks like a lawyer trying to drum up support.