The other quote says including the right to use property.
In an excess benefit transaction, the general rule for the valuation of property, including the right to use property, is fair market value. Fair market value is the price at which property, or the right to use property, would change hands between a willing buyer and a willing seller, neither being under any compulsion to buy, sell, or transfer property or the right to use property, and both having reasonable knowledge of all relevant facts.
In other words, the value at the time of the gift of the life lease would be the amount that a willing buyer would pay to use the property for that amount of time (to buy a lease or to rent it).
3ABN gave them the right to use the property as long as they would live. There was a dollar value to that gift even if it was not stated at that time.
It would seem that if as Nosir Myzing said May donated it to 3ABN, it would be reasonable that she could request to be given a life lease as a condition of the donation and thus reserve a life lease during her lifetime. But 3ABN gave it to the Sheltons also and we do not know if she required it. But whether or not she requested it, the Sheltons were disqualfied persons.
What did the Sheltons give in return for the value of the life lease? If they did not give fair market value for the life lease. It was an excess benefit transaction. Their position as founders and officers made them subject to rules of law that an ordinary person would not have to obey.
Edited for correction of grammar and for formatting.