Maybe xe ain't so wrong after all.
If your friend has been there a few weeks, then yes he would have got 74 baht to the pound, but the pound has fallen a bit against the dollar over the past couple of weeks. I think I'm correct in saying that the baht is generally tied to the dollar, so the pound has fallen against the baht as well.
You say in another thread that it's been 4 years since you got less than 70 baht = £1. I was in Pats 3 yeras ago and I'm sure I only got about 66 - 67 baht to the £ (that was for travellers cheques). Where do you change your cash/atm?