Lucky, I totally agree that they should have asked regardless of the circumstances - regardless of what was written in the birth plan. So much happens in hospital births 'just because it's what we do' when I really think consent should be sought. I have a client whose baby was born at home but then had to transfer in to SCBU because he needed some help breathing (he was a bit early). Not long after we arrived they whisked him off and when they came back to us he'd already been given several medications, including antibiotics, without the parents consent. If they'd been asked and given genuine reasons why they thought he needed them they probably would have consented but they, and I, were furious that they never had the chance to have a say. Grrrr.
I'd say it's definitely worth chasing up. Are you planning to birth at the same hospital this time? If you can kick up a fuss now about your last birth you might find that getting a bit of a reputation as someone who will stand up to them will help you with this birth.
This time, I've never had a section, but as a doula I've supported several people who had a c/s in the past and have then had a vaginal birth the next time. I've a client in just that situation who is due any day now so I'll let you know how that goes too if you'd like.
Gina. x