Lets look at the numbers, roughly as I no longer fly the 73.
Holding for 45 minutes at FL 100 - 1,5tons
Divert to Teeside is about 60 miles so lest call it 350 kg including the approach.
Ga and divert to NCL about 50 more miles another 500 kg with a 3 mile final approach.
So if they landed with just above final reserve (lets call that 1200 kg) :
They arrived at LBA with just over 3.5 tons (about 1hr 20minutes endurance), held until they had just over 2 tons (about 50 minues endurance), carried an approach at Teeside and a on the ga they had 1.7tons (about 45minutes endurance). Landed in NCL with 1.3 tons (just over 30 minutes endurance).
If they landed with 2 tons add 700 kgs to all of the above and 20 inutes endurance.
All very rough figures but either way it seems to me they did OK. If they declared a PAN and landed with 2 tons is perhaps a little overcooked if they landed with just over final reserve I would not have bothered with Teeside. Personally I would be after a rock solid alternate at that stage. In any case all legal and acording to the rules.