Why did the Blood Guanyin Forest break its hands and feet?

Mrs. Tang planned it. The plot of Lin Duan's broken foot in the movie Blood Guanyin was planned by Mrs. Tang. In order to let the Lins' property fall into her own hands, Mrs. Tang deliberately let those who seduced the Lins, and after the Lins were killed, she left Lin Bianbian. Mrs. Tang deliberately kept Lin Bianbian, broke her hands and feet, and pretended to be Kyle to kill people. This arrangement, on the one hand, is to damage the image of Lin Pian in the society, and on the other hand, is to make the investigation direction of the case point to Marco, thus covering up Tang Fu's real crime.