All curbs and offsets of roofing surface are vulnerable to fracture and puncture. There shall be reliable support for waterproofing membrane at any given point of roofing. Those photos show upturn roofing leg, where bithumic felt is alredy punctured - perhaps by tips of workers shoes (see white shoe tracks).
All concave corners shall be smoothly filleted with filler (i.e. mortar) or cant strip fastened. An empty glass bottle makes excellent shape tool .