borq646,
A bit of a reach, but here goes...
I had a very similar situation. *3 was administered as the FAC for SAC activation. When this particular person completed a call, they had this nasty little habit of pressing *3, which is also 'delete' in the voice mail system. Not sure what they were trying to delete, but as I said, a nasty habit. Most of the time these tones would just go off into nowhere, but at times, they would have a dial tone and... you guessed it, SAC activated.
