It most certainly shows someone, but the issue is who that person is. If it's taken to mean that the makers of the video allege the subject is a former employee (but, hypothetically, she may be an actor), then it makes fair grammatical sense. Though "showing an alleged former employee" would be less ambiguous.
Not that I'm saying that's the case, of course. It seems to me that if Ms. O'Donnell wasn't whom she claimed to be, then the damage control department at Planned Barrenhood might have, er, alleged that by now.
I see your point. It isn’t proven that Ms. O’Donnell was a StemExpress employee, so it is fair to say that the video shows an “alleged employee”. But at the same time, I don’t think that Ms. O’Donnell’s employment status at StemExpress is what is in dispute here. The dispute is whether she did the things at PP centers that she says she did. That’s why I think that the “alleged” needs to be attached to her role as a StemExpress employee.