Perhaps the boys anxiety issues and desire to sleep in Mum's bed are more to do with the fact that Mum and Dad are no longer together- something that the poor kid is reminded of every time he wakes up- than any lingering memory of a few moments in an overhead locker.
The shame is that this is reported as 'news' rather than someone 'calling' the woman on it and telling her that being separated is far more likely to be affecting her child than anything what happened on an aeroplane.
It reads as though the CSM may have been wanting something on the F/A to make their job easier- or that they thought that if they made the pax do the leg work that they wouldn't bother and we all would be none the wiser about what is a pretty insignificant event. Let's be honest, what parent out there hasn't playfully thought about and/or pretended to put their toddler in an overhead bin?