Executant

The hostess, who played no instrument, but doted upon all, was of opinion that an executant should 'aim at mirroring his own nature in his interpretation of a tone-poem'; whereupon another lady threw out remarks on 'subjective interpretation', confessing her preference for a method purely 'objective'.

[…] no composer or dramatic poet has ever pretended to be able to perform all the parts he writes for the singers, actors and players who are his executants.

Also of importance are the other theatricians - the costume designer and/or executant, the lighting designer and/or executant, the technical director, […]

After all, Cave speaks about orders being so manifestly illegal that the person carrying them out must or ought to have been aware of their unlawfulness. From this alone, one can draw the conclusion that, if the executant of the order actually knows of its unlawfulness, he ought to be convicted, no matter whether the order is or, as in John Doe's case, is not manifestly illegal.