I’m not sure that many clubs bother appointing an interim manager for 14 days?
She was a caretaker manager until a decision was made regarding a permanent appointment. That's all she was. They had a friendly or two in that period and understandably wanted someone to steer the ship in that period. With the season approaching a permanent appointment was always going to be made pretty quickly.
On this basis, Lewis and Fazackerley should have got the permanent Oxford job just because they oversaw things on an interim basis while a managerial process was taking place. The furore surrounding this is totally ridiculous and indicative of the delicate world we are in.