That's confirmed in a letter released today by the U of A.
The letter was sent by UA Athletic Director Jeff Long notifying Bobby Petrino that he had been fired.
In it, Long outlines the reasons for Petrino's firing, including this:
"You admitted giving $20,000 cash to Ms. Dorrell as a "gift. Ms. Dorrell used the money to purchase a black Acura during the first week that she worked for the football program. Among other concerns relating to this "gift," you should have disclosed this fact to me when you recommended hiring Ms. Dorrell in the football program, but you failed to do so."
Earlier today, UA officials confirmed that Dorrell has been placed on paid administrative leave but released no other information about the matter.
The complete firing letter is attached below.