I don't see it the same way as the TV commentators seem to. They're trying to decide whether it was Ralf's fault or not, but it's more complicated than that.
If you remove Kimi Raikkonen from the equation, then it's clearer cut. Rald moved and moved and moved across the track. He went from his grid slot to the other side of the track, past Rubens' line. He was being quite extreme. And the irony is that with his Williams' superior power and launch control, he could have stayed straight, and he would have arrived at the first corner first, and on the racing line. Without Kimi therefore, Ralf was unquestionably to blame.
However, Kimi
was there. This changes matters. In response to Ralf's movement across the track, Rubens moved also, thus squeezing Kimi. The penalty really arises from Kimi's accident, not from any discipline issue. Therefore, Rubens should have moved
toward Ralf, thus protecting himself from a Ferrari/McLaren accident, albeit increasing the risk of a Ferrari/Williams accident. If Rubens hadn't moved, Ralf would have had to stop moving, and that would have prevented the Raikkonen shunt.
Ralf (and this was the core of the Williams defence) couldn't have known that Kimi was there, and that's fair enough. However, Rubens
did know that Kimi was there, and by continuing to move in response to Ralf, Rubens caused the shunt. Therefore, Rubens was to blame.
IMO, of course.