It would be untruthful to call this anything other than what it was....user error. Nonetheless, something of abstract interest. Was photographing in the bear swamp in the morning and my favorite antique car farm near Washburn WI in the afternoon. I forgot to turn the dark slide over to the exposed side when done with the swamp shot and exposed the same sheet of film on the truck. Makes me reflect on just how many other mistakes are commonly possible during moments of mindlessness with a view camera:
Forgetting to close the lens after focusing and shooting wide open at full aperature
Pulling out a dark slide in a holder that you thought had no film in it.
forgetting to change the aperature and shutter speed settings, either on the camera or the meter.
moving the camera when inserting a film holder.
Applying more movements with the back or front standard than you have lens coverage and not noticing the vignetting on the ground glass.
Give me time and I will discover more :-)