People assume oil clubs cheat all the time, when in fact it's just them finding legal loopholes. Which UEFA allows.
One needs at least a super basic understanding of law. Legal matters are supposed to be written, and taken, as literally as possible. So if loopholes exist, then they're not illegal to exploit. Not until the lawmakers plug the holes.
I find it funny how everyone's complaining about oil clubs now that FFP exists (and they're allegedly cheating it), but forgets about how Milan, Chelsea, United etc. used to outspend everyone through cash injections from the owners, when there was no FFP.