I think that you are probably right to be suspicious. The R22 uses a sprag clutch mechanism, thus...
As I understand it (but am more than happy to bow to somebody who understands the type far better), the sprag clutch is effectively a centrifugal mechanism which engages as power comes in, but should automatically disengage if you lose power - so that you can still autorotate after an engine seizure. If you're getting a delays rotor start after clutch engagement, my guess would be that somewhere in that mechanism something is out of tolerance - which could similarly delay disengagement if you had an engine failure (or practice autorotation), with a potentially fatal outcome since you'd not maintain rotor RPM.
Incidentally there have been problems with this clutch mechanism before, there were eleven failures in the late 1990s which were tracked down to faulty manufacture - fortunately this didn't lead to any fatalities. The result was replacement of about 1000 clutches worldwide, and Robinson winning US$7½m from Dana, the clutch manufacturer, in a court case.
Finally, I'd suggest reading the memo below.
G
