To your question...."would RVX need permission from Novo disk for that link"....

I don't think they would need permission....its Twitter after all, and anything that is put out there can be retweeted by anyone, I'm not 100% sure on this, but I think once you put something out on Twitter, its out there and can be retweeted by anyone who wants to.

But nonetheless it is interesting that Resverlogix would choose to retweet a video from another company.