My apologies for getting the wrong Arrows driver, but the rest of it stands!

Even the FIA think that Button could not avoid de la Rosa...
"FIA Press Release
Pedro Diniz is left on the grid at the start of the parade lap and so has to start at the back of the grid. Before the race can be started, however, Alexander Wurz suffers engine failure in his Benetton and the start has to be aborted. As the Benetton spare car is set up for Giancarlo Fisichella, it looks as though the Austrian will not be able to start. Diniz is able to take his usual position on the grid as a result of Wurz's misfortune. At the start Michael Schumacher gets into the lead with Jarno Trulli second but almost immediately the race is stopped because of a suspected computer error in the starting software. Red flags are not shown around the circuit, apart from at the start-finish line. As a result there is an accident at the Grand Hotel hairpin
when Pedro de la Rosa tries to drive around the outside of Jenson Button and the BMW Williams driver does not have the steering lock to avoid tapping the Arrows into a spin. This creates a traffic jam with several cars stopped and others having nudged into those in front. The race is stopped. Button, Ricardo Zonta, Nick Heidfeld, Pedro Diniz and Marc Gene have to run back for spare cars. Gaston Mazzacane and Jacques Villeneuve are able to drive back while Pedro de la Rosa had no car available after his accident in the warm-up. Zonta and Diniz are able to start from the grid as the teams take the cars out before the pitlane closes. Wurz, Button, Gene and Heidfeld have to start from the pits."
It is time there was better / faster info to the flag marshals, or else lights over the track around the circuits - the same happened at Silverstone last year, MS crashed AFTER the Red flags cam out becuse the message had not gone round the track - something to be said for in-car repeaters of the warning lights eh?