There are two different FSS examination reports showing two different silencers, which were examined and show two different pieces of evidence - one paint, the other blood. These documents are uploaded to the Forum.
Whether this means that something untoward has gone on is a matter for reasoning and interpretation. I have not said that or made that claim. I only say what is on the Forum.
If my recollection about the particularity of what evidence is on what is mistaken, that doesn't change the fact that there are two different examination reports for two different silencers with - inevitably - two sets of forensic evidence.