PlanetsCentral

Fairly often when playing the Privateers I get this message:

We have encountered an enemy ship in space, but we haven't been able to board it.
Our transporter chief says this was just a random misfortune that can happen from time to time.

But almost always I don't think it's a real rob failure. Is it possible that PHost checks all ships with mission Rob and applies the random chance-to-fail, and sends that fail message even if there wasn't any enemy ships for it to rob? If so, wouldn't it make more sense for the fail-check to happen only if a ship is actually attempting to rob an enemy? Or is there another explanation as to why I'm seeing this message so often, yet never seeing any of these mystery unrobbable enemy ships?