You have it backwards. If this was happening in my team I would look at why there is a misalignment between company expectations and employee behaviour. If an employee needs to create a script to pretend to do something then there is most likely a deep cultural issue coming top down from management. It highlights an opportunity to refine and improve work practices and culture. The fact that an employee would lie is already a huge red flag that there is something wrong with the culture. Sure 5% of the time the employee is actually not fulfilling their duties but you will know this without the call logs because you would miss them on the call.