It seems to me that the Torah decides in Lot’s favor (unlike the view of Nachmanides, who holds that Lot did not act properly). Had he not taken in the angels, Lot would not have been saved. The angels appear at the gate of Sodom, and their appearance is a test for Lot. At first they refuse his invitation, and that only intensifies the test. Lot, who invites them in, knows what awaits him from his neighbors, and also knows what awaits them if they remain overnight in the street. He chooses to sacrifice himself (- his daughters) in order to save the lives of the guests, whom he feels he cannot abandon to die. In return, Lot merits that his family is saved by those same angels whom he brought into his home. And even though the scale tips in his favor, the judgment is far from unequivocal, and Lot is punished in the cave when he has relations with his daughters.