A few comments from the ATC side :
Listening to the VHF recordings everything sounds normal there: It looks like ATC did not " suggest" an intersection dep and pilot knew where he was as he repeated T1, and took the line up and wait at T1, and later the take off clearance from there.
Unusual situation to ATC ? no, some departure are made from T1, and the controller is not there to ask " are you sure" everytime someone does. He/she will get funny replies if they did.
As to a 777 long range not using full runway,and " only " 2600m. and why controllers did not flag the problem to the crew :
Controllers today , especially the young ones, are not trained to detailed aircraft performance numbers, too many types and engine variants around, and the actual T/O weight is not distributed to them anyway. The aircraft could be empty and/or with minimum fuel , or making an intermediate stop , a last minute change not mentioned on the departure strip, etc..many possible factors why ATC will not normally challenge an intersection dep, especially one with 2600m left..
Lastly, on a lighter note , seen the average knowledge of geography of my US friends and colleagues, I wonder how many really know where and how far Doha is ..
