Is it possible to force the iPhone to disconnect ( programmatically , of course)?
Not on a phone with an unauthorized call, no.
Programmatically, you can program the lego logic bias set to simultaneously press the top button and the home button until it shuts down; -)
As already mentioned: No.
In general, the answer to these questions is pretty simple. Ask yourself, "Can this feature be used to interfere with the iPhone as a phone?"
If yes, then no, you cannot do this.