Sherburn are big on EVERYONE joining over head, and nobody swooping in straight onto final, so it's unlikely he just came outta nowhere (honest guv'). As you most likely taxied out on frequency, you should have been able to hear that character making calls for "overhead descending", "downwind", "base" and "final". If he didn't, then that's his problem.
I don't buy the turn around and exit the runway theory. Actually it's one of the silliest things I've ever heard, no offence. What else would you consider doing, add full power and run off the side of the runway, just so someone can land?! It must take all of 25-30 seconds from entering the runway to being well out of the way, so I think you were just unlucky to get a "flapper" who probably heard you, saw you, then panicked when he could have easily continued and landed safely behind you.
Most likely it was some miserable old sod who noticed you were an "outsider" and wanted to give you a hard time. He probably kept his speed up on final just to be aggressive and make a point. If he wanted to go around from 3-400 feet, that's his choice. So while I'm not recommending landing on the back of someone, I wouldn't bin an approach just because someone's entered a runway. If the guy in fronts wheels aren't off the runway before I start to flare, then I'd worry.
In all my time at Sherburn (on and off for 10 or so years) their A/G was mostly a chat frequency anyway, and "correct" radio procedures (of the sort I experienced at Thruxton, Old Sarum, Blackbushe etc) were often lacking. I think you gave the guy plenty of warning from your "ready" call, so he should have spoken up then.
Don't let that put you (or anyone else) off from going back there though!