Touzi00

The case of whether the door was locked or not was discussed even in the law court meaning that every person who is involved should think about it (husband+mistress), not only that It was not a secret that the wife was thinking whether she missed to close the door or not so surely her husband and her friend were well aware of it. Meaning that if the topic was triggered definitely anyone involved will think about it and both of them will surely then knows that she was the last one to get out of the house

Yes I do agree but what I still don’t get it is the husband trying to put the blame on the congresswoman when he certainly knows that the door was last opened by his mistress

It appears that the protagonist's friend/sister inadvertently opened the door, as she was involved in an affair with the protagonist's husband. Due to her child falling ill and her sudden return home, she hastily concealed herself, intending to flee when the wife entered her house. However, in her haste, she failed to close the door properly.