Thanks all for your comments and advice.
Yes, I think there was an Alitalia, x2 Air Europa and a Ryanair flight that I could have caught earlier (but wasn’t allowed according to Iberia) so definitely worth investigating the rules on this further as I was delayed by over seven hours.
And it is also true that they did not ask for volunteers… I asked other passengers as they were boarding! Plus the check-in agent pretty much said that was the case too.
Not checking in online was silly on my part, but yes it was a multi-destination ticket not a connecting flight.
