If the hanged girl was facing the door, how does it face the window in the photo taken from the balcony of the neighboring building.
In the scene when Cassinelli and Ralli are looking at a strip of film footage, they repeatedly stop the projector to pause on a single frame. However, the shadow of the projector plainly reveals that it is still rolling.
When Cassinelli and Ralli are using a film projector, they ask the operators to reverse the film. The film starts again at the footage asked for, without rewinding.
When the motorcyclist is machine gunned by the police at the end, you can clearly see pieces of gaffer tape holding the squibs in place in the back of his leather jacket. In the next shot, when the police examine the body, the pieces of tape are gone.
If the killer already killed a driver while chasing the attorney, there was no reason not to kill the old man while killing the woman.