It's a possible implication, depending on the amounts, the frequency and how that relates to acceptable accounting standards, but it's possible to have broken the PL rules (e.g. by misrepresentation to them), but not have broken UK law (fraud).
What it is is an easy tag to use for the hard of thinking.
Had this discussion with the legal eagles on here. My pov was that there is a valid contract in place between Etihad and the club, for example. The services under the contract were provided and the services were paid for by Etihad in full. So irrespective of how Etihad came across the money to pay the club, even if it came from Mansour's petty cash, the accounting fundamentals in the club's accounts were correct.
Their conclusion was that, for the alleged breaches to have occurred, assuming the same issues as at CAS plus maybe one or two others, then they would be implying fraud, whether they actually state it or not.
CAS even stated (something like) accepting UEFA's case on the Etihad transactions, for example, would involve a conspiracy between the management of the two companies, their directors and auditors and the experts called before CAS (I am paraphrasing here because I can't be bothered to look it up) and, presumably Mansour himself. That was one of the reasons they couldn't find for UEFA.
On the other hand UEFA also explicitly said they weren't disputing Mansour's evidence that there was no hidden funding.
So I guess it's a legal thing, which I don't really understand, and this, after all, is a legal procedure.