Dom sat in his hospital bed allowing Mina to punch him in anger. Normally he would have blocked some of her blows, but he was enjoying himself too much to stop her. Somehow Mina's outburst let him know that whatever happened, was not as bad as he imagined, and he had imagined the worst.
When Dom had first met Mina, he was already aware of what happened between the woman and his boss, and at that time, he was indifferent toward the girl. He did not believe that she was innocent as it was claimed, but after getting to know her, Dom realized he was wrong.
Dom knew what Mina lost during her encounter with President Lee; it was mentioned to him when his boss thought he and Mina had been sleeping together. Then the fact that Mina had only been with one man was stressed to him after his boss found out that he had been mistaken. Dom knew the information was shared to deter him from Mina, but no matter how he tried not to think of the girl, she was always on his mind.