daz you say that but last Monday was exactly the same story, 7 flights scheduled after 1am but I was on one of about 30 or so after that time, and around 50 in total arrived after midnight. Jet2 may or may not have got their luggage quicker, but their delays were far longer in the first place.
In fact there have been big problems every day for a week or so. My flight was actually cancelled the day after and again on Thursday.
Most London airports have had problems, but STN (and SEN) have had the double whammy of European delays AND poor weather (especially fog) of their own.