The GUR just confirmed the operation. A Russian Mi-8 carrying spare parts for fighter jets was lured into Ukraine in an operation that lasted over 6 months. Two crew members (unaware where they were heading) were reportedly eliminated while the Russian pilot was kept unharmed. He is reunited with his family that was taken to Ukraine earlier.
"Official information will be forthcoming. In advance, there is such information. We need to wait a little, the work will be done, including the crew. Everything will be fine, there will be news," said Andriy Yusov, a representative of the GUR.
Could also be that they defected and reported that they were killed, to protect their families from retaliation.