Relief pilot of a B767 felt that fuel should have been jetisonned prior to landing when they returned above maximum landing weight to the departure airport due to a passenger illness.

Narrative

Climbing through approximately 12;000 FT; cabin notified of passenger in distress; convulsing; difficulty breathing and defibrillator in use. Passenger stabilized; but in moderate distress and unable to continue for remaining 10 hours of flight. 100 miles north of ZZZZ; decision to return to ZZZZ and land. I recommended dump fuel. Altitude was FL320. Captain directed reference to checklist; which I accomplished and was just about to begin jettison. First Officer disagreed and Captain ultimately disagreed. No fuel jettison accomplished; although at least 20 minutes were available; with no delay in landing. Captain declared medical emergency. Captain and First Officer flew back to ZZZZ at high speed. Final approach was a shortened turn on and fast. Landing weight determined to be 372;000 LBS; which was 62;000 LBS above maximum landing weight and roughly 20;000 LB above flaps 30 degrees speeds; therefore a flaps 25 degrees speed was calculated and flaps 25 degrees configured for landing. Approach and landing flown by Captain. Pitch control was poor; power control erratic. Approach never stabilized. Landing was long; but due to poor runway lighting and markings at ZZZZ; touchdown distance could not be determined. Touchdown was normal; descent rate less than 100 FPM. Brakes manually applied at 140 KIAS. Rough 180 degree turn accomplished at runway end to taxi back to parking. Ultimately in chocks; a tire overheated and deflated. Brake was cooked and had to be replaced. In retrospect; I should have been more insistent that the flying pilots dumped fuel and set up for a more normal stable approach and landing.