Well....IANAL, but until my youngest did not want to go back to CC (several years ago), I rarely got stamped. Mainly because, my wife and daughter were already there and I just walked in and right by. When I would leave with my daughter, she would ride with me instead of my wife......we just walked out. Only once was I questioned for not having a stamp when exiting...I told them she was my daughter and continued to walk out with my daughter.
Caveat: I haven't been to CC in 3/4 years.
My take on CC detaining anyone is questionable, including the child.
My oldest daughter works at a place in the mall; they have Code Adam. Their protocol is to have a leadership person stand at the door looking for the child with that description. If located, alone, they will ask them for help. However, if accompanied by an adult, they will 'request' them to stop; however, if they don't, they provide the description to the police.....in addition, they will follow them in the mall and premises until the po-po say stop.