I've seen that diplomat thing all the time, even in vanilla. I usually get tired of them wasting 5 seconds of my time and assassinate them.

The spy thing is probably something like he tried to leave the city and move to a certain tile, but it was on the other side of a river or something, and there was an army on the bridge. So to get to that tile, he had to backup the long route to a different river crossing. But since as the bird flies it is only two tiles away the game seem ok with moving a long distance. They will do that sometimes. Don't know if this is your case.