From actual experience:
DC10-30
Decelerating on base leg, approx 210 kts & 5 degrees NU, Flap 0/EXT selected (extends slats). Left outboard slats did not extend. Full right aileron input plus about 2/3 of full right rudder required to keep approx straight & level. After cycle back to UP/Retract and back again, normal conditions returned. Scary moment....