What are theses defects on this shot - Ilford HP5 pushed two stops on a Kiev 88 with a light leaking film back

I got a used Kiev 88, 80mm Volna lense, and shot this with a film back that's evidently leaking light (see camera right). It was Ilford HP5 ISO 400 pushed two stops.

However, I have no idea what caused the defects (see the red circle), and I've only seen it with that shot. Subsequent rolls only had light leaks if I used the wrong film back.

Any ideas?

Answer

It looks like static discharge damage, that is electric sparks from friction when handling exposes the film emulsion. I used to do these figures for fun a long time ago. Happens before processing, when the film (and you) is wet it will not happen. Probably when handling the film in or out of the camera/cassette. After or before the real exposure.