At 72 minutes when he 'cuts' her forearm, in the very next long shot there is no visible injury. Minutes later a mark reappears on a different location of her arm, then continues repeatedly changing in appearance.
In 77th minute, the stabbed homeowner, from a position seated on the ground, manages to stab the other man under the arm (physically impossible reach).
At 1:10, the 'blood' and injuries to her face look like smeared caramel.