For starters, why do you need an actor to “demonstrate what not to do in the workplace”? Couldn’t they just secretly film employees on any old regular Thursday and get the footage they need? Then you could do a candid camera type ending where Jim Turley jumps out and cans their asses.
As far as casting is concerned, David Hasselhoff immediately comes to mind but in the off-chance that the Hoff isn’t available, who picks up this gig? We imagine an in-house choice would be preferable in order to save on costs.