The advantage is pretty clear from where I stand: His passing attempt was ludicrous, he went very wide, and yet he lost no time. That by itself is worth a drive through penalty if he's gaining a competitive advantage by doing it, whether he's passing someone or not. He did gain an advantage, and that's already worth a penalty.
Just think about it: If nobody is following their car closely, would anyone actually try to trace a chicane under those conditions? The 'penalty' of having to slow down so that the car right behind you catches you if you just passed him illegally is a low price for the lowered risk of accident. When every turn is a death trap, the 25 second penalty seems cheap.
One could also argue that, if Kimi was ahead, there's no way he'd have gone to the wall. He was driving desperately and it showed.
That's not to say that the 'red car rule' isn't still in effect. Just that in this case it was the right thing to do, regardless of the liveries. Now, the alonso penalty is a different matter, but I'm pretty sure most McLaren employees were happy about it anyway