No, I've no idea at present. What mistakes did you notice?
"While a sound moderator was being forensically tested, the other was being photographed at White House Farm, one was SBJ/1 the other DRB/1. It is, of course impossible for the sound moderator in issue to be in two places at once. Photographs img – 3642. CR2 through to img 3649. CR2, picture the rifle and sound moderator in the gun cupboard on the 20th September 1985. While photographs img – 3650. CR2 through to img 3653. CR2, shows the rifle with a different sound moderator attached in the gun cupboard on the 11th November 1985. Thus the photographs of DRB/1 were taken on 20th September 1985, and the photographs of SBJ/1 were taken on 11th November 1985."
They make the argument that the moderator was being forensically tested the same time as it was being photographed elsewhere and can't be in 2 places at once but then fail to establish with evidence it was being forensically tested on the date the photos were taken. Instead they discuss dates in 2 different months. It is quite possible for the gun and moderator to be in one place one month and another place in a different month. It is possible to be in a different location the same day as well though so long as they are different times and someone transported it from one location to another.
The moderator didn't sit at the lab it was brought back and forth to the lab and once the blood was removed it didn't need to be tested much, the testing was mainly to the blood.
The argument doesn't seem well thought out.