Experiencing massive hair shedding within the 8-12 months after hair transplant is normal. The lost hair will grow again 3-4 months later. After this temporary shedding has recovered, the transplanted hair follicles preserve their characteristics and they are not shed.
Hair growth has phases; growth phase, dormant phase and shedding phase. Transplanted hair is permanent for life time and cannot be lost unless you develop alopecia related skin infection.
In the meantime Dr. Civas advises couple of things to prevent further hair loss. However, the original hair in the same area may continue to be lost and a new hair transplantation may be planned depending on the decrease in the hair density.