It depends on what you attempt to communicate. If you say "Some were filmed", you're refering to the process of making those videos. You're talking about the past, how people got to record them.
However, if you said "Some are filmed", there would be a slight difference. You would now be describing the characteristics of the videos. "They are filmed" could be attached to the physical features of them, such as the scene. For example: They are filmed in the Big Theater. They are filmed in the middle of the storm. Or, as you pointed out, They are filmed by men who these women thought were their friends.
Of course, these videos were recorded in the past. But, as the author is trying to describe the videos -the evidence we have today-, he uses the present tense: Some are filmed by men...
Did it help? Hope so! I have to admit, I had to think it carefully! Otherwise, let me know! See you!