WIllowfly
but I think the engine surge is also completely possible - would this cause a large bang?
Yes, like a huge car backfiring.
You might find this video interesting
YouTube - 777 PW4000 Engine Surge on 747 Testbed
I fly as a passenger nearly every week and I know that experiencing an engine surge would upset me - so I take my hat off to you for getting back on to an aircraft and then sticking with it.
