Cruise Control problems of the 2014 Ford Escape

Vehicle was being driven approximately 65 mph on a highway in moderate traffic at the time of the incident. Road conditions were dry, outside temperature was cold (<32 degrees f). Vehicle was being driven on a route that is often driven with this vehicle. Vehicle has approximately 40k miles with no known mechanical problems. Driver routinely uses cruise control almost every time the vehicle is driven. In this instance, driver attempted to engage cruise control and the control engaged for only 1 sec before automatically disengaging. Driver attempted this three more times to the same effect. At the same time as this cruise control malfunction, the driver was receiving a cellular call on an iphone 6, service with us cellular. Driver did not pick up the phone but continued to let it ring. The iphone was sitting in the drivers left front pants pocket. On the fourth attempt to engage the cruise control, it failed again but after another 2 seconds, immediately engaged without input from the driver. When the cruise control engaged, it engaged at 72 mph, causing sudden, unintended acceleration from approximately 67 mph to 72 mph. Driver disengaged cruise control and then continued to drive normally. At this time, the iphone also stopped ringing. Continued driving since that time - with no additional calls received on the iphone - have no had any further effects on the cruise control. Unknown cause for cruise control malfunction, but given that it is used frequently every time the car is driven for commuting without problems with the exception of this instance, driver suspects emi/interference.