I’ve come across certain sites with this approach, as the contractor is not trained on the device or has either lied on their glorified CV. If an incident was to occur which was due to an engineer making an error and they were required to attend coroners court, how would this be approached?
Also some OEM training certificates have expiry dates on them, who is responsible for recertification, would it be the engineer or the trust they are working for?
For mandatory training the responsibility should lie with the line manager and/or HR.