Engineers" will not guarantee that this type of incident will not happen again as they are as fallible as the next human being....
You either didn't read or didn't understand my post. You can push the aircraft around at 1 inch an hour and not guarantee a collision. Your chances increase as speed does. An Engineer is in nearly all cases going to be vastly more experienced than a baggage handler and the likelihood of a collision will reduce dramatically. For this function, an Engineer is not as fallible as the next human being.