So the long & short of it is (by my understanding) is, the PL brought in APT to stop sponsor companies associated to a clubs' owner, from agreeing inflated sponsorship deals as a way of getting money to the affected clubs through the back door. The thinking being this would unfairly distort the transfer market.
From City's viewpoint, we argued that the way APT's are judged is unlawful, because the PL adjudicate what they view as fair market value sponsorships, based on a database of previous sponsorship deals. HOWEVER, if a club disagrees with the PL's decision, they're NOT allowed access to the sponsorship database to challenge the decision.
On top of this, director loans aren't included in APT or PSR. Director loans currently held by Arsenal & others are interest free / very low interest, so City effectively argued why weren't these loans also considered to be a backdoor way of funding certain clubs. The independent review body found in our favour on these points.
It was also found that the amount of time the PL took to adjudicate against City regarding the Abu Dhabi bank & Etihad deals (2 & 3 months respectively) was unreasonably long, & found in City's favour in this respect.
City also alleged that these rules were created specifically to target owners from Gulf States, but the panel ruled in favour of the PL.
In terms of the legality of APT itself, the panel found it to have a legal basis, but with serious flaws with how it was constructed.
This is what's led to both sides claiming victory. APT remains, but must be amended so City & others can review the sponsorship database, & the PL must also include director loans in APT. OR the PL can scrap the lot & try coming at us with something else.
This is my short form understanding of the situation.