Has anyone else been told by Jet2 to claim on insurance after a cancellation/delay?

TLDR: I was denied boarding as the plane was full and jet2 refused to acknowledge their reroute obligations under Regulation 261/2004. They told me to claim accommodation and the flight home on my travel insurance. Was this a one off or have other people been told the same?

I was flying back from Geneva to the UK and when we tried to check-in we were given a bit of paper saying we had been denied boarding as there wasn't room on the plane. There was a link to a relatively complex jet2 doc explaining 261/2004. As there were no jet2 staff in the terminal I called the UK helpline and even after a 1hr+ phone conversation they refused to acknowledge any obligations to accommodate and reroute under the directive - when I asked this question they just ignored it. They explicitly told me to book accommodation and flights home and claim on my travel insurance.

We paid ourselves and got home and I then filed a claim which has (almost) been successfully paid in under 2 weeks. I'm keen to understand if this is a one off or a systemic approach to minimise costs under the directive.

I should add that my motivation for this is that most people probably aren't me - I've got 2 masters, have recently spent most of my days negotiating contracts (not a solicitor), and secretly enjoy finding out where companies are in the wrong. They may have not succeeded in fobbing me off but I think I'm probably an outlier.