I have a Plantronics Edge UC (not the Lync version). I also use an Apple Magic Trackpad and Logitech K811 keyboard with my rMBP and with my Mini Server (I have two sets, one for each Mac). The UC version of the Edge ships with a BT 3 dongle (for dictation, Skype), even though the Edge is BT 4 compatible.
About 19 times out of 20, when my Edge UC is paired with my Mac or iPhone and the iPhone gets a call my mouse cursor goes absofrickinlutely nuts - dancing all over my display screen with Sound Effects Pref Pane feedback going "nuts". I moved my Edge UC several feet away from my Macs and connecting cables - no problems since. I'm not chalking up the conflict to my BT device but, rather, the unshielded cable that shipped with my Edge UC handset - I'm going to buy some shielded cables in the next couple of weeks. I've noted similar issues with unshielded USB 3 cables, FWIW.