The DTCC needed to validate the officer of the company requesting the change of the TA as well as the replacing TA credentials. An officer of the company should notify the DTCC. How that got by the DTCC is unknown to me. But the DTCC also needs to validate the certificates also. I understand there were glaring mistakes in the counterfeit certificates that a rookie should have caught.
As you recall, Megas stated time was on his side. Thus the reason for fading memories is a plus for Megas and of course the infamous SOL.