Take all defection stories from Russia Today with a grain of salt- here’s what they had to say about the flagship of the Ukrainian Navy:

She joined the Naval Force of the European Union (EUNAVFOR) in early January 2014 for anti-piracy operations. As she refueled in Greece while Russian forces seized control of Crimea, Russian media claimed on 1 March 2014 that the ship’s crew had defected to Russia and raised the Russian flag.[7] Shortly afterwards, independent news organizations reported that the ship was still flying the Ukrainian flag in port in Crete.[8] The commander of the ship confirmed that the crew had never defected to the Russians.[9]