MS was on their way to losing when they negotiated the settlement. If it had been the other way around, Apple would have had to pay, not just make IE the default browser.
Maybe maybe not. MS had been threatening to pull off the platform, which would have hurt Mac immensely. MS’s agreement to keep making Office for Mac didn’t really cost MS anything, and helped Mac a lot, then MS turns around a makes a tasty profit on the stock. If what MS got out of that is for being on their way to losing I’d kill to lose some suits like that.