It looked like on the broadcast that Ibaka told Brooks and the trainer that he wanted to stay out there. He hadn't played in something like 10 days, not even practice, so he may have felt good and wanted to stay in the flow.
But I agree, I was calling for them to take him out. No matter how good he feels, every second he's on that court is another chance for that hamstring to get re-injured, and our season is over if that happens.