Oops... I should have been more specific... in 35mm Still photography, or for cameras that had a 'curtain' type 'shutter' mechanism, one could get partial frames depending on the shutter speed with a flash... because for higher shutter speeds the 'curtains' would just be open enough for a slice of the film to be exposed and that 'slice' would travel from one side of the film area to the other, or from 'top' of the frame to the bottom, depending on the implementation. I think 35mm mostly were side to side curtains...
The other type of shutter, the leaf shutter as part of the lens assembly, did not suffer from this sort of thing, as it was ether fully open, or closed, thus avoiding 'partial' frame results...
Since I don't have experience with Film film motion picture cameras, just on theoretical grounds it seems like they could also produce partially exposed frames depending on the speed of the flash, un-sync'dness with the shutter, etc. but perhaps less 'readable' than the block type artifact of the 'rolling shutter' digital read out pattern.