I'm not gonna be saying R* wasn't exploiting. But i'm almost sure that those 100 weekly hours weren't "work". They needed people to be there at those times because they were passing material from one unit to the next one, and based on the final state of the game, they'd have to be there to pick it up. That doesn't make it any less crunchy for you, but it doesn't mean you're writing code or modelling for 14 hours straight a day. That's impossible to achieve. So I feel they just were "there". Maybe you'd have two hours where you're just standing by for the other team to finish their commit on their code branch. Not even QA can work that many hours because things would slip through based on exhaustion alone.
Doesn't make it right though.
To imagine the scenario, you're a coder for whatever branch of the AI logic. You push the changes and they playtest whatever changes happened to see if things break. Now you're 3 hours just minding your own business because the game is literally finished unless more things arise. But at the same time, you can't go home after working 8 hours because the review might come at hour 9 and then it'd need another day to get fixed. It's complicated to sync when you're running out of things to do and now every segment of the team is not in sync