Unlike the cancellation/delay, duty of care, and downgrade provisions, EC 261/2004 only imposes a "reasonableness" standard on the operating carrier. Going through the folly of asking OP whether he would prefer to abandon his child into the care of local child welfare authorities or wait behind with the child strikes me as affirmatively unreasonable.
The entire issue of whether the agent made a call and, if so, to whom, is a red herring. Bright red.