Tahiti is France. No extradition to US, which is why Roman Polanski is still a free man.
Grabbed this from Wikipedia (which isn’t the gold standard of accuracy).
Polanski’s case is a bit different from Snowden’s. Polanski is a French citizen, Snowden is a US citizen. France and the US do have an extradition treaty, and it is Polanski’s French citizenship that seems to be the only thing keeping him secure (France does not extradite its own citizens).
Thank you. Probably why he chose it to write his memoirs, or whatever he’s doing there.