That seems to be one issue. No lawyer but I would imagine it's a pretty normal legal principle that changes can't be applied retrospectively. At least, it can open up accusations of bias and unfair treatment.
On the KC, I said at the time it was stupid of the PL to appoint an Arsenal season ticket holder. It's not really about him being biased, it's about opening the process to the accusation of bias. Stupid to give the opportunity for an additional 6 months delay and millions of pounds more costs when they could have chosen someone else. Even appointing him because he is their "chosen" KC who has represented them before opens up accusations of bias from continued appointment. Surprised if City really go that route, but stupid mistake by the PL.