Sheep,
Yes, the possibility that he transposed the digits when tuning the ADF is certainly within the realms of possibility.
Ultimately, it doesn't matter *why* he took the route he did, and really, it doesn't even matter what the route he took was. As far as actually finding the aircraft is concerned, the most relevant part is the flight of the aircraft after it was identified by Williamtown radar at 320M/45nm at about 1936. We know it was there, and pretty much anything before that isn't very relevant in finding it.
From that time, until it lost contact, was about 3 and a half minutes.