Personally many reasons in my opinion. Firstly he is the head of a football club in a league with the biggest global spotlight. I don't think it is a good look to be going on the attack and calling into question Wilder unless specifically asked that question. Secondly it begs the question why the need to do this, is it because he himself has been feeling the pressure/attacked and is defending himself. Is it because he himself is similar to Wilder in that he is never to blame and he is shifting the blame on to Wilder? Is it because he is hiding something? There are many ways to be deceitful other than outright lying; omitting valuable facts, prioritising certain stories over others, avoiding the question, and a very commonly used one embellishing (politicians are noted for many of these btw). His answer to the first question on the video contains at least one or two of the above, possibly more but as we don't know the truth we can only guess at some. His first answer contained many 'facts' that intended or not created a narrative that Wilder was not committed, was hard to work and deal with, was selfish, and that he is motivated by money, and I may have missed some. It seems this worked a treat as following the interview this board was littered with threads and themes such as 'Wilder is not one of us', 'Wilder is selfish and lacks fight', 'Wilder demanded 4million' etc..
Of course PA may prove to be telling the truth but there are many reasons to look at that interview beyond the words and be a little sceptical I would say. Of course Wilder is equally culpable but some seems to have had an alarming about face from this interview, and I would suggest this was the whole point of PA doing it.