When Ruth Ellingham gets the gun from the son, Michael Dunwich, Ruth carries it upstairs to Mrs. Dunwich's bedroom. When the scene switches to the Mrs. Dunwich's bedroom, the gun is on the bed already next to Mrs. Dunwich, in the very next scene, it's back in Ruth Ellingham's hands and there's nothing on the bed.
When Mr Newcross is being administered CPR by his granddaughter, Dr Ellingham arrives and asks "Can you hear me, Mr Dunwich?" Dunwich is the surname of two other characters.