There is no "proof" that anything released to date is or is not authentic. Trial should be interesting. In mitigation, both UHC & LM will deny/confirm what they choose & evidence will be presented. If the Maglione family produces solid evidence that her diagnosis & timeline of events involving treatment, unneccesay delays causing renewed deductible periods (common insurance ploys utilized to increase profit margins), etc, & proof that he was with his mom during these time periods, if there are witnesses to her intractable suffering, etc, then we can at least say that *yes*, his actions are directly linked to UHC policies, even if inexcusable.
I also have zero doubt whatsoever that this highly trained experienced tech engineer would know how to set things up to have an explanation of his actions made public after his arrest. I'm equally confident that UHC would use every means at their disposal to suppress any and all damaging information to the fullest extent of their abilities.