I don't think we can assume that teams flew to Frankfurt at all!
This assumption was made because:
1. Production was seen flying to Munich.
2. The only other flight to Germany that night (for the teams) was to Frankfurt.
But it could very well be that production was skipping ahead to Leg Five - Turin:
Asuncion to Ciudad del Este: 2 Dec 1120-1200, to Sao Paulo 1220-1500;
to Munich 1715-0800, to Turin 1055-1235
Which means teams could have been trying to go somewhere completely different for Leg Four.
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Looks like the Kiwi poster was on AR 1182, leaving Buenos Aires at 2.30am on the morning of the 28th.
The Miami connections arrive in Buenos Aires at 8.24pm (Aerolineas Argentinas) and 9.56pm (American Airlines). Aeromexico via Mexico City arrived at 8.49pm. All are too early for her departure, unless she arrived at the airport reeally early?
Or TPTB booked teams onto this really late connection:
CM 303 from Los Angeles to Panama City, 27 Dec 0058-1028
CM 363 from Panama City to Buenos Aires, 1546-0056
Note that Buenos Aires-Salta flights leave from AEP, not EZE.