I would also add the opinion that it was a non event.
It would seem that they held at Leeds until they were down to the fuel they needed to divert to the commercial alternate, but knowing that the weather there was a bit iffy they had put enough fuel on the a/c to fly an approach and if needed then proceed to Newcastle which they knew was wide open.
Isn't this what we do every day (the fuel planning, not the diversion)? I certainly try to in such circumstances, and only if limited for take-off mass only have fuel for the second alternate (in this case NCL) missing out the first choice. It all seems sensible, they complied with JAR OPS requirements, they did their best for the company (and almost certainly kept ops informed through handling agents or direct) and had a back up plan as well that worked.