It was interesting seeing Raikkonnennkonnennkonnen (I can spell it, its knowing when to stop) smoking to a stop in practice. Something about water and Italian auto electrics. Perhaps the Ferrari lot should have a look here for hints and tips.......
The truly dumb aspect of holding the race at that time was, as BY says, the entire world that has access to local knowledge is aware that around there you can pretty much set your watch by the start time of daily rainfall, and this has been the case since the place was discovered by people from the Western hemisphere. Starting a max 2 hour race at a time to miss the daily deluge is not rocket science, but if they needed to apply a bit of science, it is possible to delay transmission by an hour or two, and call it "delayed live". Provided transmission started before the actual event ended, anybody wanting to avoid finding out the result before watching would have a good chance.
Or they could put a great big gazebo over the entire course. Sort of like the Millennium dome, only useful.