You might be experiencing reaction behavior which results when something like a tank shell hits an area near infantry. This results in the user losing temporary control of the squad as they react to the oncoming fire.
Consider this an added property of certain attacks. A flamethrower or PTRS can both cause this type of behavior as an example.
NO this happens almost ALL THE TIME. 1 squad versus another, NO TANKS, or MOTARS or anything in the area. Dodging grenades needs to be easier. Also, NO ONE in ther RIGHT mind RUNS INTO FIRE, so why do some of my troops!?!