It was put in a holding pattern over the peak district whilst ascertaining the validity of the threat on board.
So, once it was ascertained that there was no credible threat, why did the Typhoon then have to escort the airliner all the way to Manchester?
It would surely not have been permitted to proceed had there been a credible threat of any kind whatsover, so the cynical inference is that the purpose of the continued escort was to achieve lots of publicity.
Not saying publicity is bad - if it shows the other bad guys that the interception capability is there, all good.