It's like the book without a copyright page. It does not mean you are free to do with it as you please. I would not make such an assumption.
Try this. Ask the author.
On the 'Properties' tab of videos, in the Summary it may show Origin\Summary\Protected No. Does that mean that the vid is not copyright protected and that it can be reposted online, such as in an open forum, with no claim made as to rights? Thanx!