please note that the rule I quoted has changed in May:
3.6.7 If a lack of progress occurs in the evacuation zone, all victims (including ones that have rolled) will remain in their current position. Victims that are held by the robot will be placed roughly on the location of the robot when the lack of progress occurred. If a lack of progress occurs as the robot exits the evacuation room whilst carrying victims, the victims will be randomly placed in the evacuation zone.
There is no limit about how many times the victims can be thrown back into the evacuation zone.