Vitaly Nayda, Ukraine's director of informational security was on CNN saying they taped a conversation between Moscow and an officer minutes before the launch reporting that a plane was coming.
"We taped conversations" between a Russian officer and his office in Moscow, Nayda said. "We know for sure that several minutes before the missile was launched, there was a report" to a Russian officer that the plane was coming, he said.
Who knows what to believe anymore with so much misinformation, but this did seem to make some sense. I'd been wondering how the SA-11 operators initially acquired the plane with such a narrow beamed radar. It's a lot like looking through a soda straw trying to find something. It's great for tracking but lousey for searching. It can search the skies around it but it takes minutes for just one complete scan 360 degrees around. I believe it was too cloudy that day to see it and likely too high to hear. But, if they did get a heads-up report on the approaching aircraft then it would be much easier to scan a small sector in the expected direction to acquire and lock on.