A relative flew from USA to London on shabbos. Can we speak to them after shabbos in London from the same tome zone.
It is permitted. The reason is that although the person did melacha on shabbos, but it isn’t as if they made something for you that you would not be allowed to benefit from it. Additionally it doesn’t look like the person flew for you, therefore it would be permitted.
Rashba Shabbos 130b, Chayei Olam Shabbos 9-11, Biur Halacha 318-1 D:H Achas, Orchos Shabbos 25-45, Meohr Hashabbos 1-18 (ftnt. 53 in the name R’ Eliyashiv and Dayan Fisher zt”l) Also see Ashrei Ish O:CH 2-24(26), R’ Y. Cahen shlit”a., that it is not considered befitting from the actual act of the melacha.