I've had my oil pressure/STOP light flicker a few times during
some very, very hard cornering on my 505 (with XN6 motor).
It would usually happen if the car severly oversteered.
Once the car straightened out, the light would have already
gone out. I think it is caused by the pickup sucking air,
and fooling the pressure switch. I run synthetic oil anyway,
so it really didn't bother me.
Joe