Saying something is essentially "religious" means that its confirmation depends on faith—which St. Paul called "evidence of things not seen." Well, with electron microscopy, you can't say the beginning of life is not seen. I've seen the pictures. What's "religious" is the denial in the face of physical evidence of the fact that life begins at conception.
What the socially liberal fellow meant to say is that the origin of life is a fact with moral implications—which many people who are religious happen to be interested in. He finds those implications inconvenient, but has no facts to protect himself with. So he makes recourse to his "faith" that the videos do not show life beginning, even though they plainly do.
What I found amusing was that, a little later in the discussion, I said that his argument was illogical - which he chose to take as an insult as in I had called HIM illogical - and he proceeded to show the logic of his position by getting mad at me (emotional response).