Hello murgatriod and please allow me to welcome you to Flyertalk and thanks for joining this little community over here on the BA Forum. I hope you enjoy it and you sound like you have been lurking for a while which many do including myself and which lasted a couple of years if I remember right!

If you got a very good bargain/mistake fare I would keep that to yourself. Period. I'm assuming you've been ticketed and have an e-mail regarding this?

In this case I'd personally book refundable hotels etc which in a lot of cases doesn't cost that much more and is a wise insurance policy.