Help with a 1099 misc. For rental income.

My boyfriend had a home with his ex wife. She lived in the home, until March of last year. Where at that point, they rented it out through a property management place. Per the divorce he is to claim the house the odd years. He received a 1099 misc. For almost 18,000. The money that was received for rent went straight to the mortgage company, because the home is not paid for. Some months the money didn't even cover the mortgage and we paid the difference. Is there anything I can do, to show that there was absolutely no money being made, it was only used to pay the payment, lawn, pool, upkeep, ext. Because when I put the 1099 in, it killed him on taxes. Please help!!!