Between the time Donald Pleasence receives a visit from the supposed murder victim, to the time he visits a tailor to get his robes, he's gone from a slightly receding hairline to complete male pattern baldness.
One of Lawrence's legal colleagues tells him he is prosecuting a murder case with no corpus delicti. The body of the woman supposedly murdered was not found, but that has nothing to do with corpus delicti. Corpus delicti is a Latin phrase for "body of the crime", and does not refer to a literal dead body in a murder case.
Before Mrs. Malone comes into Laurence's office, a blonde woman can be seen in the background in the outer office sitting down and moving from right to left. The subsequent conversation between Malone and Laurence in that outer office is done with the implication that nobody else is in the office.