1996 Mercury Marquis Pressure Control Solenoid

My Ford dealer replaced the PowerTrain Control Module (PCM) in January 2010. In October the transmission began to malfunction. The tranny shop found a code saying that the pressure control solenoid had malfunctioned. They reset the code and the tranny worked fine. It reverted to tranny problems and threw the same code. I took it to the Ford dealer and they said that the PCM had failed and there was a sticking solenoid in the transmission. I asked that they replace only the PCM because resetting the code allowed for a functional transmission. They then stated that there was a short in the pressure control solenoid that ruined the PCM and they would not warrant the new PCM unless the PCS was replaced. I had both the PCM and the PCS replaced. I questioned their conclusions and they gave me this explanation, " The Pressure Control Solenoid stuck and reached RPM limit and caused internal damage to the PCM". I don't buy that. Is what they say true?