Barbara Allyn I don't think it is Spenser because he is not a Succesful man whose company has annual reports. It also says he enjoys the role he has been given so I am thinking Lund.
This answer contains spoilers… (view spoiler)[It couldn't be Torbjorn Ross because he's a cop and the person watching the film likes to comment in public and hide behind his company's annual reports and achievements. That means it couldn't be Spencer either because he's a professor. My guess is either Johan/Lund or some mysterious rich person who likes snuff films. It's never mentioned whether Johan is married, and Federika wonders aloud who would ever pay to watch such stuff — so I think it could be either. (hide spoiler)]