I remember landlines in the UK actually operating like this in the nineties. If you hung up, the line would stay open until the caller ended the call. It doesn't make any sense and I remember being surprised when it didn't happen when the caller was on a mobile phone.
Maybe our cable company's exchanges were misconfigured? I'm pretty sure it doesn't happen these days. You could never hang up on unsolicited sales calls for example.
Sounds like a medicine I shouldn't take before asking my doctor if it's right for me.