Pure flying time wheels up to wheels down, or gate-to-grate time (accounting for taxi time, etc)?

As a very rough ballpark estimate: It's 1,893 miles between the two airports. Taking wikipedia at face value with a notional cruise speed of 533 MPH for the 767, that would make a simple point-to-point time of about 3.56 hours not accounting for: any wind, time to climb & descend, actual true airspeed at the altitudes used for cruise by a given flight, actual routing taken, speed restrictions due to traffic, taxi time at origin and destination, etc.

Is this Thomson? Guessing because that's the only 767 operated flight on that route showing up in recent Flightaware info, which only shows 2 recent flights on that airline for the route in question (not to say there aren't other dates not shown). One clocked in at 3h43m and the other at 4h06m. So I'd guess that 3h28m is in the realm of possibility depending on winds and other conditions as noted above.

https://flightaware.com/live/flight/...145Z/GCTS/EGCC

What's the underlying issue that prompted the question?