i don't disagree with your assumption some tour operators over estimate as do a lot of charter skippers over the world. its an entirely acceptable behaviour as far as i'm concerned as long as the fish goes back alive, in the end who really cares.
as for terence when i have been across the hours are down to the clients. most people are on holiday and 9-5 suits them as they can still enjoy the nightlife and don't have an early rise the next day. horses for courses.
we did fish long days last time over some 15-16 hrs long but that is for the pure nutters amongst us, that added to 100's of miles to get to a spot.
as for fish weight Terence knew i wanted a fish over 200lbs to beat my best in the UK and despite catching a reasonable shark he didn't succumb and it fell short of the double ton.
we can only put down our own experiences and i believe there are a number of anglers on here who have used Terence and most wouldn't question his honesty in weights, neither would most of his countrymen who have the utmost respect for the guy.