NWSRG,
There are airways that head over that way and then up to LPL. It could be possible that there was ATC restrictions in the North London or midlands area and this was simply a re-file to get away on time. As for the height it may just be that extra track mileage allows the aircraft to cruise higher.
Oh and sorry to dissapoint you but I think you'll find Mr O'Neill on his way to White Heart Lane!
(Oh come on let me dream!)