Sadly it is not uncommon for airlines to "divert" for no safety reason, but merely due to the fact that the aircraft is needed elsewhere to bail out their flying programme at other bases. Without knowing the circumstances, flaming an earlier poster for having sought compensation from Jet2 is seriously OTT. The diversion to MAN could have been due to a flap failure requiring longer LDA than available at Leeds (i.e. safety related) but equally well could have been because aircraft at MAN were tech and the LBA aircraft was needed at MAN to operate the next outbound to reduce their delay - in which case, the pax inbound to LBA got the raw end of the bargain. I'd wait to know the full circumstances before passing judgement.