Okay, she got it right, though her deductive reasoning wasn't exactly watertight. As I said in my comment, we did have mixed staircases and landings. And every now and then things got mingled up anyway.
So what a stupid pointless lie. Except for the fact that the person next door to me was Allison Pearson's (note the two 'l's now, cfr!) boyfriend at the time.
A very old copy of Metropolitan, as edited by Fiction Bitch, will be heading cfr's way, as soon as I can find it.