Crossed lines: Why isn't the equity release message getting through?

True story. I once had a telephone conversation with someone for almost three minutes before realising they weren't talking to me at all. I was on the hard shoulder of the A303, trying to summon help via one of those orange emergency phones placed every mile along our motorways. It turned out that both me and another hapless motorist on the same stretch of road must have tried calling for help at precisely the same moment because we got a crossed line. For nearly three minutes I had a perfectly-timed, if somewhat bizarre and frustrating ‘conversation' with someone in a traffic cont...