OK I uploaded a video of YouTube of my various fails on the "mortar mission."
I marked with a caption late in the video where I think this movement occurs (about the 6 MINUTES 26 SECS mark)- again, my guy is stuck in this looping "crouching" animation - like he's hopping - and he just can't hardly move at all. So I couldn't reach the northern tree line to try to finish off the mortar guy.