So for a quick summary,
Lori/David, Eric/Jeremy and BJ/Tyler at Marte, BJ/Tyler
waiting on top of unknown helipad, white-shirted pair
running on top of the Blue Tree Towers, Monica and Joey
running on the helipad across the road from Caesar's, and Wanda/Desiree inside a helicopter. The white-shirted pair (one wearing jeans, the other black pants) are at Marte with Eric/Jeremy and BJ/Tyler. Unless the racers changed clothes inside the helicopter, it's none of the abovementioned racers, nor Ray/Jolanda or Lisa/Joni, seen on the Viaduto. We can also rule out John/Scott from the TV Guide photo, so that leaves Lake/Michelle, the Danielles, and Fran/Barry.
If teams don't have backpacks (not even on the helicopter, judging from the Wanda/Desiree clip), it means that they will have to return to Marte after the task. But having each team go to a different helipad will be kinda unfair, judging from the spread of the locations over São Paulo. Is this a Venetian Mask, Buenos Aires Tango task, where they are given a photo of the helipad which they are to find? (One problem with this is we may have teams landing in weird places they're not authorised to.)
Strangely enough, we spoiler people are doing the exact same thing.