I wouldnt say they are paid off but they look to please the promotors in last nights case Matchroom by giving the home fighter any advantage they can in order secure more high profile fights and extra benefits whatever they may be.
They are, all over the globe. Most not as blatant as with a brown envelope filled with 100 bills, but their accomodations, perks and their chance to get to lead another big fight for the promoter basically trigger the same effect. Plus they're clearly partial towards their "own", wich is rampant with some nationalities. No sane boxfan believes that officials are that incompetent in scoring or leading fights. If you put 3 neutral fans at the judges seats without any training they would still do a much better job as the majority of the "licenced" judges. And you could probably replace the ref with a fan after giving him a 2 hour instruction too.