OK playing outside, he could therefore have had a short nap, then woke and wandered. I think wandered is a definite possibility.
Woke wandered and then abducted is always a possible sequence.
Well if he had a short nap he must have dozed off outside. This does not seem to fit with the known facts.
I agree it is possible woke, wandered and came to some harm. KM dismisses this idea as she refers to MM as a 3 year old, whereas in reality she was a few days off 4, who would in her opinion be unable to pull the curtains, slide the patio door, open the child gate and close it and open the gate to road and close it. According to KM she also found the bedroom shutters up, window open and curtains flapping which had all been left closed hence she will not entertain any other theory other than abduction.
Children do not open full length curtains. They find the gap and move along underneath so no problem there. KM does not say MM could not reach handles etc just in her opinion MM would not be able to slide the doors, open the gates and leave returning everything to its rightful place ie closed etc. However throughout the book she repeats numerous times MM was very intelligent, knowing and advanced for her years.
In my experience children are like sponges soaking up everything going on around and are far more knowing than many adults give them credit for. MM would undoubtedly observe what KM/GM did when leaving and could simply have copied. Why not if she is/was as intelligent as KM states in her book?
Has a child psychologist ever offered up opinion about any other aspect of this case?