I can't speak to the flight conditions (temperature/windspeed) for your flight, but no sonic booms will reach the ground unless the velocity of the aircraft through the air is greater than mach 1. There are even some cases if the aircraft is travelling slightly faster than mach 1, no sonic boom will reach the ground. This is dependent on atmospheric conditions. Almost certainly parts of the aircraft experienced local supersonic flows over their surfaces (cockpit) that would result in increased boundary layer noise, but not shocks that would propagate to the ground.

763 mph is an abnormally high groundspeed. On several flights I have seen the groundspeed well in excess of 600 mph, but never 700. In fact at http://www.groundspeedrecords.com/ you can see unverified ground speed records accompanied by photos of cockpit displays with tailwind componants of well in excess of 200 knots (230 mph). Notice the TAS values being a more pedestrian ~500 kts.

Several posts around these forums have noted diversions due to unusually high headwinds flying east to west lately. I would not be surprised to see off track deviations of 500 miles (as your original post indicated) if a pilot could get 200 knot tailwinds on a flight such as TPE to LAX.