For a radar to be able to detect/recognize/distinguish the electromagnetic signature of a "roll" requires very sophisticated real-time Signal Processing, that was not available until digital computers were designed into and became part of the radar system, which did not happen until the late 60s and early 1970s (at the earliest).

For a radar to be able to detect/recognize/distinguish the electromagnetic signature of a "roll" requires very sophisticated real-time Signal Processing, that was not available until digital computers were designed into and became part of the radar system, which did not happen until the late 60s and early 1970s (at the earliest).

It could be conjectured that a very astute radar operator using a WWII radar that displayed raw returns, might be able to recognize the increase and decrease in radar signal intensity as an aircraft rolled, presenting a higher wing planform and radar cross section, in a roll, but that would only occur at beam (90 degree) cross angle, not head or tail on, not to mention that numerous other phenomena (weather, variance in transmitted signal strength, etc.), would probably cause the same variance. So it is highly unlikely that this would have useful or reliable.