The bottom line being that the unlikely condition of CE 399 and the defects in the chain of custody actually cut in favor of authenticity.
Trying to have it both ways, take one zillion and two.
If the condition of CE 399 were "likely" and it had a valid chain of custody, then it is authentic.
If the condition of CE 399 were "unlikely" and it had no valid chain of custody, then it is authentic.
This tells me that what the LN-faithful believe has absolutely nothing to do with the actual evidence.