The problem is the FEC says:
"If any person, including a relative or friend of the candidate, gives or loans the candidate money in connection with his or her campaign, the funds are not considered personal funds of the candidate even if they are given to the candidate directly. Instead, the gift or loan is considered a contribution from the donor to the campaign subject to the per-election limit and reportable by the campaign."
Rudy said Cohen went ahead and paid Stormy because it was a critical point in the campaign.
If deemed to be campaign related then the money should have been declared a campaign contribution.
It doesn't look like Rudy did Trump any favors here.
That may have been Cohen’s thinking (hearsay from Rudy at this point), but he had clear ability to go ahead and pay stuff and get reimbursed later without involving the boss.