I believe that your own suggestion is correct. News videos can be made up of various clips or items of footage often from different sources and therefore with different usage restrictions.

Here are a couple of examples that illustrate things a little more clearly:

This news video consists of 2 clips. Under Technical Info, it is stated:

Restrictions: INFORMATION FOR REUTERS SUBSCRIBERS ONLY: PART NO ACCESS SOUTH KOREA (VIDEO PROVIDED BY 'CALEB MISSION' IS STRICTLY NO ACCESS TO SOUTH KOREA CLIENTS)

Reuters own the copyright to the first clip and it is accessible to all, but for the second clip, it is stated:

HANDOUT BY CALEB'S MISSION CHURCH - NO ACCESS SOUTH KOREA
http://www.itnsource.com/en/shotlist/RTV/2011/12/22/RTV36986...

In this example, footage comes from 2 sources, Reuters Television and NBC and restrictions apply only to the material from NBC.

Restrictions on certain uses may apply, and may vary from those listed. PART NO ACCESS NORTH AMERICA/MEXICO/CNN

Then look at what it says under item 12:

(NBC NEWS --NO ACCESS IN NORTH AMERICA, MEXICO, OR BY CNN)
http://www.itnsource.com/shotlist//RTV/1997/10/26/710260029/...

Sometimes "partly no access" is used:

PARTLY NO ACCESS SOUTH AFRICA
There is no access to Clip 1 in South Africa (SABC - NO ACCESS SOUTH AFRICA</i<), but Clip 2 is accessible to all.
http://www.itnsource.com/en/shotlist//RTV/2012/09/20/RTV2088...