A1 certificate after reaching state pension age

I have an employee currently posted to Germany who is of state pension age. He has a valid current A1 certificate which dates into the tail end of the year, and we are in the process of acquiring an extension. During this time, the employee in question has reached out to the NHS services in order to renew/obtain his S1 which will keep him covered for the remainder of his time there. The agent he spoke to informed him that he now no longer needed an A1, which raised some eyebrows as I cannot find any guidance confirming that an A1 is no longer needed once state pension age is reached. Can I have some confirmation on this in case it crops up again; do British citizens posted in a foreign country (Germany) require an A1 certificate after reaching state pension age? My initial thought would be yes, as the certificate confirms social security legislation applies to them, but the NHS agent offering contrary information has confused things. Many thanks.

Hi 
If you re-apply for the employee via HMRC for both the A1 and S1.
The NHS will not issue a S1 for employees and this may be what they were referring to.
Complete both applications online as per normal.
Thank you.