The video is pretty obviously edited around the time she supposedly said
их расстреливать с ядерного оружия
Also I think the translation is incorrect - the man didn't say "what should we do with the 8 million Russians who stayed in Ukraine" he said "what should the 8 million Russians who stayed in Ukraine do" что теперь делать оставшимся восьми миллионам русских, которые остались на территории Украини