It is a little bit strange that 4 teams can race to the finish line...
But I do think that the 4th team may be fall behind a lot so that they do not appear in the finish line
Also,I think the team who don't do the roadblock,may not be Dave and Rachel,as they have same experience and they learn a lesson in Paraguay leg.
4 teams do NOT race for the Finish line. One team is eliminated in Osaka. 100%.
They are just showing a shot taken at the mat before the decoy 4th place team arrived. Common.