Gen. Maximus
Warlord
My Mongol Keshik was farming XP 3 tiles away from a Persian city by range attack 3 hexes away twice a round (logistics) when out of a blue, a Persian longswordman that completed build rush out from the city and killed my Keshik after I end the turn! 
How could that happen?! The movement max for foot infantry is only 2, not 3.
As I did save before I end, I reload and the exact thing happen. This Persian unit cover three tiles over tundra (no roads) to kill my Keshik which is on Persian side of the border. I retested by putting a Great general three tiles away from Keshik original position. The same Persian unit killed my Keshik and after I pass turn again, the unit went on to kill of my Great General moving over differnt set of bare tundra tiles.
However when I pass turn with the Keshik standing 3 tiles away but on Mongol side of the border, the Longswordman did not rush out for the kill but stay put as garrison in the city.
What is going on? Is it a bug?
How do you capture screen in Civ V btw? PrtScn key?

How could that happen?! The movement max for foot infantry is only 2, not 3.
As I did save before I end, I reload and the exact thing happen. This Persian unit cover three tiles over tundra (no roads) to kill my Keshik which is on Persian side of the border. I retested by putting a Great general three tiles away from Keshik original position. The same Persian unit killed my Keshik and after I pass turn again, the unit went on to kill of my Great General moving over differnt set of bare tundra tiles.

However when I pass turn with the Keshik standing 3 tiles away but on Mongol side of the border, the Longswordman did not rush out for the kill but stay put as garrison in the city.
What is going on? Is it a bug?
How do you capture screen in Civ V btw? PrtScn key?