It's a fact that while Sheila was being treated at St Andrews,that not everything could have been honest,given the reputation that the place has.
This fact would have been to conceal that they had a patient,Sheila,whose care and treatment wasn't what it should have been and who'd gone on to murder her family.
It's certainly not the first time that someone has been imprisoned because of a dodgy doctor,professors/consultants alike have all told their lies on oath. Police lie regularly on oath. No conscience,just thoughts of promotion and their pension.