A blogger who also happens to be a gun enthusiast and a professional photographer has demonstrated how easy it is to replicate the marks on Robin's hand. In his demonstration he shows that the marks could easily be wrinkles or cuts, and the idea that they are gun residue is unsafe. It is also rather hard to load the magazine by using the thumb on the angle which the marks are seen. Normally, when loading a magazine the marks will go parallel with the thumb. In the picture of Robin's thumb they go across the thumb.
Intersting coimments here from a poster on Kiwi blog to add to the mix,
I’ve loaded several thousand .22 rounds into magazines over the years, and have never had resultant marks on my thumbs or fingers which the pro-David Bain camp suggests is typical.
Here’s how you do it if you are right handed and are loading a semiautomatic or a bolt action:
You hold the empty magazine in your left hand.
You insert a round at a time with your right hand.
You depress each round after you insert it with your right thumb nail near the nose of the round, which of course is pointing towards you.
Your thumbnail takes the pressure as you ensure each round is placed correctly as you depress it into the magazine.
You insert the magazine in the firearm, and when you are ready to fire you ensure you have a round in the chamber by working the bolt or equivalent.
There has NEVER been any mark on the ball of my thumb or elsewhere on my fingers after loading a .22 firearm.
DAMN IT! I’ve been drawn into this stupid argument, which is being fanned by TV3′s escapee from Planet of the Apes. If only he realised, he can stay on Earth permanently as long as TV3 pays its taxes.