Just as I moved a crow one step closer to a city I got an out of sync error. When the page had reloaded, the crow had moved but no more fog had been lifted. The city's two lower tiles are still covered even though they're within the crow's view radius. The minimap displays that the fow has been lifted there though.
It's my most north-eastern crow in game 1012 if you want to have a look before I finish the turn.