"Investigators found NO DNA under the woman's remaining fingernails, or on those taken during the search of the rental house at 610 N. Buchanan Blvd."
I take it now that what the defense must have been saying then was that there was no such DNA that could be matched to any person (100%).
One would think that if there were sufficient material to conclude that it was human tissue, then there would be sufficient cells from which to extract enough DNA to make a 100% match or not, suggesting that it may not in fact be tissue but some other type of material containing DNA (saliva, e.g.)
I think you are exactly right... The fact a certified DNA lab that has put thousands of people away found no DNA... mitigates towards the fact that this was trace DNA and not tissures .. Trace DNA is transferred every day - all day.
Otherwise, if the State SBI is that far off and they were handling the Player's DNA to check for matches along with the samples from the Victim's belongings - then it can be argued that they contaminated evidence inadvertently by the inferior attention to Detail.