Dr Vanezis was not 100% the marks to NB's back were burns. It is worth remembering that Dr Vanezis was the only expert to observe NB at autopsy so it could be argued he has the edge compared with those who have subsequently given an opinion but didn't have the benefit of observing NB at autopsy.
Prof Knight seems adamant that the marks were not burns.
Dr Caruso seemed to think the marks were burns caused by the barrel of the rifle. Although I believe he did say further tests were required before he could commit.
Philip Boyce also seemed to think the marks were burns caused by the barrel of the rifle.
Were Dr Caruso and Philip Boyce told the marks were burns and therefore misled to some degree?
Consideration:
The expert physically observing marks in person is in the best position to actually assess the marks everyone else is at a distinct disadvantage and faces limitations
People who don't view the damage in person have two reviews they can make:
1) to review what the original expert recorded as having been observed and diagnosed. Let's pretend and expert describes symptoms of heart disease and yet diagnoses the illness as kidney disease which has totally different symptoms than the patient had. In that case the expert reviewing it can say the symptoms were not from kidney disease but rather heart disease and thus call the original diagnosis into question.
2) to review xrays or photos. The quality and limitations of what angles etc were photographed is one inherent limitation. Another is the simply fact that photographs can never offer the same detail as a physical examination.
Photographs are most useful when they capture things that someone who looked in person failed to address and consider. For instance let's pretend that a closeup photograph of a wound clearly shows a muzzle imprint and yet the expert totally missed it and said the shot was fired at long range. That can destroy a case where the police were alleging it could not have been a suicide because it was fired from far away.
Let's pretend for the sake of argument that the burn marks were actually bruises caused by the little knob on the end of the rifle stock. Vanezis thought the skin was seared and that it was burns. Let;s say he totally screwed it up though and it was bruising from being hit in the back with the tip of the rifle butt. What significance would that hold? None all it would prove is the killer hit him in the back with the rifle butt. It could have been before he died or after he was slumped over. There are experts who can assess whether bruises were delivered post and pre mortem but they are a very elite group and it is hard to fully know whether they are accurate or not. It takes a great deal of care and expertise that few possess.
Let's pretend it was bruises causes by the barrel of the rifle. Could the killer have struck him in the back with the barrel of the rifle while Nevill was slumped over after removing the moderator and putting it away? Absolutely. Even if true that would not establish the killer didn't shoot the victims with the moderator attached. In the meantime they can't establish for sure it was a bruise let alone a bruise caused by the barrel of the rifle as opposed to something else.
The suggestion the killer removed the moderator and put it away then heated up the rifle barrel and used it to burn Nevill is not persuasive at all and in any event would fail to prove the moderator wasn't used to shoot the victims. But in keeping with the point of this thread about experts- it should be noted that the burns they created using the barrel of the rifle had holes in the center because the barrel has a hole in it and thus there was no heated area to burn the center. So the testing they did failed to replicate the marks on Nevill's back. They lied and said the marks were the same. That is something that can easily be looked at and refuted so demonstrates why you have to actually test claims not just accept the word of experts without testing their claims.
At the end of the day the expert who examined the body said they were burns and there is nothing in his physical descriptions that permits saying he was wrong. He is in the best position to know. But even if he was wrong and they were bruises there would be no way to say what causes those bruises because the tip of any rounded object could cause bruises that size and shape and no way to prove whether they were made before or after he died.