I was on this flight, I sat in the back and did not witness the initial events however I heard the pilot say we were diverting the flight to PDX and shortly after the jumpseat pilot was led to back of the plane.

I thought he was having a heart attack, or possibly diabetic because the flight attendants were telling him it was "going to be okay" and to "take deep breaths", the guy was acting scared and non-violent.

The flight attendant later announced it was a "medical emergency" which I thought it was weird because they never asked if there was a doctor on board. The pilot later explained that there was a "disturbance in the cockpit and we will likely board a new plane". Finally after we landed he was escorted by police.