This is a shocking incident and I’m sure the said Knuckledragger will be brought to book, and rightly so. However, I’m sadly not surprised the crew did not take the correct action. I once witnessed a jumped up base supervisor ‘briefing’ new Cabin Crew that they were expected to take abuse from passengers as part of their job, and should never offload anyone as it caused delays. Truly shocking and one of the many many reasons I moved on a long time ago.