I'm in the UK and have bought all my 3.0 and 3.5 books here. None of them have anything but US printing and pricing information on them or in them. (Spelling is uniformly American throughout.)
There haven't been British editions of D&D itself since the period between the end of the seventies and the early eighties, when Games Workshop had a licence to print UK editions of books and modules. GW also used to print Traveller, Runequest and a few other Chaosium games under licence, as it happens. As far as British D&D material was concerned, TSR's licensing to GW ended prior to 2nd edition. In fact, it ended before the 1st edition AD&D books got their facelift in 1983-4-ish. Whether TSR UK ever printed UK editions of US modules and books, I'm not sure but I don't think they did. (They did, however, publish Imagine magazine, an RPG mag with considerably less editorial weight than Dragon was carrying at the time.) The GW versions of 1st edition MM and PHB were softcover, too, though GW's DMG was hardcover. I don't know if GW produced hardcover PHBs or MMs. Again, I don't think so. (I worked in a branch of GW as a part-timer while I was studying for my A-levels, between 1981-83.) As I never touched Basic D&D, I have no idea whether GW ever produced a version of that. I did once have a copy of OD&D (sixth printing) and I'm kicking myself now but I can't remember if that was a British edition (or even if there was such a thing).
This is usually the bit where I sigh before lamenting the loss of my old roleplaying collection but not today. I met an old friend recently who said, "I've got something of yours," before handing me a monochrome-covered, 1980 GW edition of G2 The Glacial Rift of the Frost Giant Jarl, in near mint condition, and a copy of T1-4 The Temple Of Elemental Evil in fair condition. (The latter is US; there was no UK edition of that.) Yipee! I also now have a lead that may have located much of the rest of my collection in a certain loft, and... Oh. Sorry.
Anyway, your friend is mistaken.