I crashed my bike a couple of years ago and hurt my shoulder, went to A&E, got xrayed and was told nothing was broken, arm got put in sling and lots of pisstaking from everyone. Two weeks later get a phone call from the xray department saying the consultant had had a look at the xrays and he'd found a break!!! Went back in, got re-xrayed, the break was pointed out, looked like the people that decide whether there's a break or not are the machine operators!!! Doctor noticed it straight away and seemed not only pissed off it had been missed the first time but also miffed as it seemed to happen quite oftenn!!! Finally ended up getting some sympathy after that!!!