One example of a model being tolerant to flight with a winglet removed or a wing tip folded does not imply that all will be. It all comes down to the aerodynamic impact of the failure / incorrect configuration. This is directly related to the size of the affected portion of the wing. One must pay attention to all impacts in all axes: lift, drag, roll, yaw, and pitch. The robustness of the systems that confirm correct configuration prior to takeoff and prevent wing fold from occurring during flight must be consistent with the hazard category for the resultant aero characteristics. For sure the impact of a single wing tip being folded while the other is correctly extended and the impact of both being improperly folded have been carefully analyzed. I can imagine that the asymmetric configuration of one up and one down may be much more of an issue than inadvertently taking off with both in the up/folded position.