Yes—this strongly points to a shutter fault, not simple user error. On the Canon 7, the shutter uses two metal curtains that travel across the frame. If the curtain timing is off, the trailing curtain can catch up to the leading curtain, leaving part of the frame unexposed. Problems like this often show up more at the fastest shutter speeds.

A common cause on older cameras is dried or sticky lubricant, but the fix is usually the same: have the camera professionally serviced (CLA: clean, lubricate, adjust). A repair technician can check curtain travel and timing properly.

If you want to confirm the diagnosis, you can test at a long exposure and inspect whether the shutter opens evenly, but be careful with the camera and lens while doing so. Overall, the symptom in your sample is a classic sign of shutter curtain timing issues.