No, I don't believe that. And the United States Olympic Committee apologised on Thursday to the people of Brazil for the behaviour of the American swimmers. I know some kind of arrogance may cause turbulence during the final bidding year. In the past there are some instances where South American countries did vote united against another bid. African representatives the same. And even Madrid 2012 and 2016 commitee had a bad feeling of fellow europeans voting against Spain. Chicago 2016 bid had lots of arrogance but in the end the bid lost for other reasons.
LA2024 is a much stronger project. I did visit LA in december (great city!) and the only turndown there is the huge traffic congestions. And I am from São Paulo - a city plagued with traffic problems. The driver in LA even joked "-Well, the same number of cars here!". I think the major issue on "Rio 2016 operations" is actually the traffic and the slow public transportation. And guess what... last week european journalists said the last time they saw this kind of problem was in Atlanta 96. I used a lot the LA subway system but it's a small network and very slow and at times looks very dangerous. I spent more than one hour to get from Koreatown to the Coliseum (5 miles) using the public system (not in the rush hour). But the venues are there only needing some work for the Olympics.
I have a strong feeling the IOC wants to bring the Olympics to Paris in 2024. Even in Brazil this message is clear by the coverage of officials talking about the 2024 games. Maybe because France was very smart to send important people to Rio to sell the bid. Even president François Hollande was here. They look more passionate about hosting the Olympics. Time will tell.