Reading back-copies at random and 366 turned up.
One observation: in the Letters page, there's an account of ghost-hunting in the Treasurer's House in York. A line in the letter reads
In that time, sounds recorded included: sandals walking on a hard surface, someone breathing near the microphone....
I can get that you can record footsteps, from whatever source. But narrowing it down to sandals just by sound alone? Do sandals make a perceptibly different noise on a hard surface compared to enclosed shoes or boots? And "sandals" in this context suggests a pre-existing association, an inbuilt bias, depending on the thing everybody knows about Roman soldiers, that they wore sandals. Therefore if you're investigating a haunting by Roman soldiers, the sound of footsteps on a floor where Roman ghosts have been reported previously... must therefore be sandals.
Two other things wrong with this:
i) Roman soldiers in Britain in the early days did wear caligae sandals as standard issue . But the Roman ghosts in York, from visual descriptions in other reports, appear to be from a later era, dressed for or marching in inclement weather. The Roman army in Britain soon experienced British winters, and the caligae sandals (more suited to places elsewhere with better weather), were "retired" seasonally, for something like a modern boot. Three centuries later, when the Romans left Britain, boots were standard all year.
ii) The word "sandals" today evokes something flimsy and less substantial, generally womens' wear. Sandals of the Scholl or flip-flop type do make a distinctive "flapping" noise when the wearer is walking. However, the Roman caligae was military mens' wear. It had a very substantial sole with metal studs in and was secured very comprehensively. I'm guessing it would have sounded like a far heavier boot or shoe.
if they're so sure it was a sandal, what were they picking up? While the letter says "staff were instructed to stay away during the investigation", people elsewhere in the building still had jobs to do. If they got the "flip-flop" sound via a sensitive mike, might they have been picking up a nearby female employee, of the sort who switches street shoes for comfortable sandals when she arrives at work? She might have thought she was outside the range of the mikes, perhaps.....