Your argument is that a brain which is functioning so poorly that it thinks it’s a reptile will be convinced by some piece of paper from a lab? That’s an interesting thought.
There are nice, somewhat tight garments waiting for them. DNA tests are a waste. This if funny farm level delusion, assuming they're not doing it just for kicks. Such beliefs to me are an indicator of a malfunction and just like having your towel with you is an indication of being prepared for everything and that you probably are in the possession of a lot of other useful stuff so is this idea one that comes with a high probability that you have more garbage rolling around in your head.