Whos responsible: tubeowner or sponsors?

Had a nice discussion last night with another GFY member and we couldnt agree on this subject. So i thought, lets see what others think about this matter.

This is the case:

- A sponsor XXX (adult company, or its rep) applies for a sponsoraccount.
- I check out their sites and videos, and i register for an affiliate account.
- I check if the rep is really with company XXX.
- I put up the right banners matching their XXX websites and their content on it.
- The sponsor XXX (in this case a rep or an uploader hired by this company XXX) uploads their own choice of videos. From 10second clips, to xxminutes, whatever THEY think is good for their own sales. Its THEIR content, they bought it, they upload it.
- The contentprovider who sold the company XXX the videos doesnt want the content on tube sites. Or doesnt want them to be longer then xx seconds. He holds the tubeowner responsible.

Now, these are the statements:

A) Is the tubeowner responsible for the videos XXX company uploaded? Or is it company XXX who bought this content?
B) Is the tubeowner stealing videos, and could a lawyer hold the tubeowner responsible?

We are talking about legal sponsoraccounts, from legal companies, that bought these videos and are clipping and uploading them theirselfs after aplying for a sponsoraccount.

Ps. tubeowner and contentprovide dont feel hate towards eachother, but loved to discuss about it without sugarcoating it ;)