Its very possible that MS paid T2 the money as a simple advance, just like a record label would pay an artist an advance on their next album.
At the same time, given T2's cashflow issues at the time, it wouldn't surprise me if it was a flat out payment for the 2 lots of DLC and Rockstar won't see another cent. However this would also be a risk as they could provide a crap product, so some sort of incentive must exist.
Never argue with idiots
They bring you down to their level and then beat you with experience







