ijnek - one thing i am sure of is that his gear ratio was fine, chris (oasis) is one of the top drivers in Aus and certainly knows what he's doing in terms of gearing.
all the posts above basically say that a possible cause for the temp shutdown is that esc's get hotter under partial load than at full throttle and he would have been using partial throttle msot of the time in the wet conditions, thefore the speedy would have been hotter.