This is very similar to American 191, where an engine fell off on takeoff from a DC-10, the predecessor to the MD-11. That was attributed to bad maintenance practices that compromised the engine mounts to the point of failure.
Im not completely surprised that UPS aims the parts cannon at problems, especially for older planes like this. They, like all airlines, are under a lot of pressure to keep their planes in the air. If they are in hangars they aint making money.