This is very interesting, first of all, that he said this. He was really put on the spot, and he had to acknowledge that even though she went about it in a very bad way, there was no other way (maybe) to get him to repent of his breach of covenant. So he makes a judgment that what she did was "less bad" than what he did.
It is also very interesting that he determined, right then and there, that he would never have intercourse with her again—even though, by the act of what he did, she was now his wife. I do not know if he remained celibate from that time forward. But at least, I guess, to him it was committing incest. So he never repeated that mistake again—which is "growth" for the kind of man that we know Judah to be. That is, willing to sell his brother into slavery; willing to go in to a priestess of Ashtoreth; carousing there while they were shearing their sheep up in Timnah. He did not really have a very good character.
