If you had read my post properly, you would have seen that I also referred to the other typ of phone which has one button - which needs to be pressed for a second or two before the call is cut off.

All phones have buttons of some sort to disconnect them. If the one-button phone isn't pressed long enough, the call remains open. unsuccessful attempts to replace the receiver will be heard loud and clear as a clunking sound by the person on the other end. This is what Thomas described in his deposition. He described the background voices as speaking simultaneously with this clunking sound.