This bloke did the wrong thing and he got arrested. No one is contesting that.
Travelling with young children is one of the most stressful undertakings as a parent. Some times you don’t think rationally.
The reality is that if the Cabin Manger just simply facilitated a seat change then none of this would have happened period.
This is not the cabin crews fault. It’s the absolute lack of customer service training that takes place. Train your crews to follow the rules and procedures while taking a compassionate approach! But as we have seen time and time again there is no culpability in the QF group.