My biggest dread is the aircraft behind me that I can't see (we have no rear view mirror). I get paranoid when I hear someone call final when I'm on final and can't see him/her. I think I'd carry on in a very straight line and have an urgent word on the radio.
I reckon G did exactly the right thing in keeping on - but I think I'd have been more vocal on the RT. I'd file an airprox, too, if I were on final and had called it, and then got "overtaken".
I don't like mixing it with microlights - had a scare at Popham last year when one cut in front of me doing a very tight base and final.