An experienced burglar? Surely he took precautions to avoid capture. Cap, gloves. In and out quickly.
MM was a precocious little girl, she may have awakened... given the situation with revolving checkers (parents alternately checking on the their own and the others' children), she might have been more curious than alarmed. Maybe he neve entered and easily lured her out, promising to bring her to her parents or see his puppy.
IMO it's more likely that he abducted MM in the course of a burglary than a dingo absconding with a baby. Or a little girl from the very tent her parents are in. And we know those have actually happened.
Scary how fast.
JMO