Factual error: At the end of episode 6, we see Alain crossing the German French border in a European registered right-hand drive Citroen CX. Then at the very beginning of Episode 7, they check into a hotel and the Mercedes parked in the forecourt was also right-hand drive. (00:01:00 - 00:01:30)
Episode #1.7 - S1-E7
Continuity mistake: Monique is making "tea" for Stephanie. She is stirring the drink and suddenly the glass is way more empty. (00:25:13)
Episode #1.6 - S1-E6
Factual error: The Indian police officer who arrests Sobhraj after the jewel robbery is a detective sergeant. The Indian police do not use the rank of sergeant. Head constable is the equivalent.
Episode #1.1 - S1-E1
Factual error: When talking on the balcony about the jewels he just sold. Sobhraj states for an ounce they could be sold for 15,000 Euros. Obviously Euros as a currency didn't exist in the 70's. (00:35:26)
Suggested correction: He doesn't say "euros", he says "guilders." Guilder was the Dutch currency used in the Netherlands at the time.
Other mistake: When Nadine met Knippinberg for the first time and narrates the incidents, he asks where Alain (Sobraj) is now. She says they have not arrived back yet. While it seems that Dominique has long been gone, but Nadine receives letter from Dominique the same day Sobraj returns. This was also the same day when Dominique was leaving the airport, and he saw Sobraj in the same airport.
Suggested correction: When Dominique was leaving the airport, he thought he saw Sobhraj but that man was not Sobhraj. In fact, this man was holding his child at the arrival gate. Sobhraj, Monique and Ajay did not return the same day Dominique left Bangkok.