Lateral movement of brick veneer caused by repetitive movement and repeated patching of mortar. This is where the urge to patch a brick wall shoud be suppressed. By repeatedly patching this brick wall every time it shows signs of movement can create a worse problem. This wall is actually moving horizontally a little bit each year as he patches it. The mortar he places in the crack acts as a fulcrum causing the brick veneer to move laterally. Strange but true. He should have done something to minimize the radical seasonal changes in the moisture content of the soil instead.