20milesout
Fully agree with your statement. Had the same suspicion but not eager enough to post them.
Looks very much of another case of a misled "believer" ! A fuelgauge is never as accurate as some might believe it is.
He should have refuelled either after that short Dortmund - Arnsberg flight before leaving for EDWL, or after the short hop over sea on the nearest mainland airfield. Because, as everybody knows or can check in multiple sources - there is no refuelling possibility at Langeoog airfield