Case C-451/20
Thank you. This is indeed very interesting EC judgment (but apparently not published in English but all kinds of other European languages).
The interesting part is the conclusion: "this Regulation does not apply to flights which has been booked together and which consists of two legs to be operated by a Community carrier when both the airport of departure for the first leg and the airport of arrival for the second leg are located in a third country, while only the airport where the transfer takes place is located in the territory of a Member State".
The other part/question was in fact also interesting. OS rebooked the pax to TK on a flight scheduled to arrive 40min after the originally booked OS flight to BKK, however, the TK flight was delayed by 1h47 min which meant that the actual arrival time in BKK exceeded the original arrival time by more than 2 hours. Airhelp claimed that this made the pax entitled to 300 EUR for cancellation of the OS flight. OS denied this stating that TK was scheduled to arrive at BKK within 40min of original arrival time and OS was not liable for any delay of the TK flight (not a stupid argument IMO). This Q was not dealt with as the EC court found that the EC regulation was not applicable at all.