When does a delay become a cancellation?

[ExXB]

Very good question

From your explanation I would say that your original flight was cancelled and you were re-accommodated on a different flight.

However, that in itself doesn't mean that you are entitled to compensation under the EU Regulation. For very good reasons Compensation doesn't apply in cases of 'extraordinary circumstances', which has no specific definition, but generally means outside of the airline's control.

If, for example, your original flight did not operate because the airport was closed - you are not entitled to compensation.

Now, if you don't mind going into the reasons why the Captain didn't operate as scheduled we may be able to comment if you are entitled to compensation.

The EU Regulation is a 'dog's breakfast' very poorly written with very big holes in it.

Edited to say: "When I say 'you' I mean, your colleague. Sorry!"