Flying buddy and I were talking the other day and I wanted to get some other opinions. He works at a large flight school with there own Mx and they from time to time ask him to run the airplane after it is returned to service. Often, dependent upon the mx done, he sits in the run up area and runs it for 15-20 minutes with a mechanic in the plane. Is it okay to log this although there was never intent to fly? Just seems kind of desperate to me and I was curious if this is frowned upon at a 121 interview? Opinions are appreciated in advance