[semanticist]

I also live in Scotland and I've had this happen to me in the past.

It almost never happens by accident - the person keeping the line open is paying for it, after all. (Or, traditionally, was, with bundles and free evening/weekend calls, I've no idea if people actually pay for landline calls any more.)

[ownagefool]

I believe it's common that T&C's will state you will be charged if you're on the call for more than an hour, regardless of free/unlimited minutes.

I've still never experienced this. I'd test it, but I haven't had a landline in a while.