It's good that they closed the loophole, but I don't think BAR should be penalized this time.
They did follow the rules and it was the rule that it was poorly designed/written.
besides, the new formulations will introduce additional "gray areas" and make it discretionary to the stewards to judge the conditions of an engine, when they are not in the position to do so.
The BAR behaviour was an obvious
prediction, but at least they were honest in their position. What if button had a spin, or a minor contact early on. would the retirement become justified then? Should he have caused a spin and retire on the grass?
Two additional scenarios come to mind:
1. we will see additional "accidents" towards the end of the races, leading to "legitimate" car retirements
2. we will see teams screwed up for the next race because they managed to get through to the end of the race with an engine damaged by external causes, but decided to keep going.
So either they implement an objective way to assess the condition of an engine after the race (likely impossible) or they get rid of the stupid rule.