I decided to see if I had an autosave that would allow me to reproduce this. It turns out I did, and I made a save that starts with the battle. However, since a random map is chosen each time, the bad map comes up only about every fourth or fifth time. I did get some more screenshots.
Here is my scout under the rock.
Here is my scout at the left corner.
Here is my scout at the bottom corner.
If anyone wants to try the save, here it is. It will probably be necessary to load it several times before the bad map is used for the battle.
