revenge perhaps?
since only two of the flights are now operated by the aircraft with the slightly red tint, one LHR to BRU in the early morn and the late BRU to LHR, and remembering that sabena sold all their slots to DAT just after they came to a stop, perhaps he sold a slot that is not really being used at present.
and if the price is right, selling is all part of business.
what ever the reason, he's done a bit better than i have.
cheers;