You have asked a very pertinent question. What is the use of doing a hair transplantation if the hair falls off in a short time after the transplant? The life of a hair follicle is dictated by the genes and the location from where the hair is coming from. The Hair follicle at the back of the head, in a narrow band extending from one temple to the other, has long life. The rest, falls off as soon as its life is over. If you transplant from this narrow band, then you can be assured that the transplanted hair will behave like the donor area hair. However, if you transplant from an area that does not come from this narrow band, then the hair will fall off as soon as its life is over. This is exactly what must have happened in the cases you saw.