The Revelation's Clairvoyance ability can produce out-of-date information.
At the start of a game scout an unoccupied planet that is near a hostile empire, and then carry on running your own empire ...
During this period that empire will most likely colonize that system.
Later on, if you then use Clairvoyance on that planet it shows the hostile empire's structures and ships, but the planet still appears to be unoccupied.
It almost looks as if the planet has recently been abandoned or bombarded.
If you then send a ship to that system you can see it very much occupied and has a healthy population, ie hasn't just been colonized since using Clairvoyance.
