Sorry, we are going to disagree forever on this.
As for your information, my experience about 'scientific method' is not that 'limited' as you guess. I instead make the educated guess that your idea of scientific method is rigid and wrong.
A stetement like this - under the POV of scientific method - is riddled with arbitrary and vague concepts. The term 'precautions' is totally vague, it doesn't mean anything itself. It might have to do with a concept of technical procedure, that is within a very limited scope, but itself is totally vague and doesn't mean anything on a scientific point of view.
The term 'contamination' without any specification is also totally vague and, itself, irrelevant to the point. The fact that 'contamination happens' is itself irrelevant, because we are not interested in the generic phenomenon of contamination (as I said, moreover, any DNA finding is itself contamination by definition).
Again, the term 'properly' has no precise meaning.
But the whole point is beyond these aspects (which are epistemology and not law).
The legal question is not whether the DNA findings (we are talking about at least two DNA findings now, but in fact there are more on the scene) are certain under a 'scientific' viewpoint or not. This is not the question. The question is whether they are pieces of circumstantial evidence. And evidence is not about scientifc realities, but about historical events, themselves defined as unrepeatable and often unverifiable events. So pieces of evidence must be, by definition, not subjected to technical/scientific cautionary paradigms.
So, sorry, the point is absolutely not in the terms how you put it.
The evidence assessment does not obey to cautionary standards put by other disciplines, but instead makes its own assessment, and assessment is based not on others' standards but on probability assessment about historical events. If your alternatice 'innocent' explanation is that you have a theory about contamination, which is a theory about one specific issue of contamination from Meredith's DNA on one unique and specific item, then you need to provide an explanation about a mechanism that describes the event and document the probability of its occurrence.
The rest, is just making up how law works.
Yes but this is just your arbitrary assessment about others' 'reputation' (and based on a falsification of facts).
Facts are that the laboratory never prevented the defence to access data of any kind.
Facts are that the defence chose to not attend the test, to not access the laboratory. Except Prof. Vinci who requested to access the fingerprint analysis laboratory and to analyze the pillowcase, no defence expert ever requested raw data nor access to laboratory documentation over the nine month investigation.
Moreover, the defence did not even request the raw data at the prelimiary hearing (as the transcripts and the defence themselves documented). The defence requested the rawa data the first time by the end of the first instance trial (yes it was the end of the trial, after all witnesses had been heared and evidence had been already discussed: after what we call the discussion phase).
And finally, Stefanoni never refused to offer any data: it was the judge who decided the late defence request was inadmissible.
This is what others here would call a 'pedantic' argument. Physicians don't wait for matemathical proof, they do work with uncertainity and incomplete information, but uncertainity is not equivalent to absence of clinical evidence. They obviously decide tretment only on evidence, or on factual grounds that this is necessary.
Btw, just like physicians, judges work with imperfect and incomplete pieces of information too.