Just what exactly is the safety lock to prevent accidentally starting the motor? I consider two different actions to be sufficient for this rule. Is this correct?
As you know, the CIAM wording on the matter is this:
"Safety locks must be used to prevent unintentional restarting of motor(s)after the motor(s) have been stopped."
I and many others flying electric classes in Britain interpret it as meaning unintentional restarting by 3rd parties, although this isn't explicit. When I was working (for an aerospace & defence company), simple safety interlocks were judged to be compliant if they met what was termed the "two event criteria". This is in line with your comment, and provided two completely separate actions are required to restart the motor I would argue that it complies. A requirement to power up the system again and then press the motor/timer start button should suffice as they are two discrete events.
.............on the other hand, sometimes CIAM moves in mysterious ways