Sounds like skrangerpro and FlightSpanner above have put a time and position on the transfer switch error. The radar flight path shows a zigzag over Dalkeith and the main tank level was low enough to get transfer pump warnings. If both pumps were switched off over Dalkeith and then the wrong ones switched on for the return journey that would explain all.
Confusion when all the warnings came up, pilot knew he'd turned the pumps back on so had to guess at other causes.