The BWF laws do not recognize words such as tempering or manipulating of the shuttles. Only words such as modify and damage to the shuttle to the extent the speed or its flight is changed are recognized. So stroking the feathers, even adjusting each individual feather, or shaping the feathers with your fingers into proper shape, so long as they do not modify or do any damage, is not a problem. Any modification or damage to the feathers are clearly verifiable and easily checked by the umpire. It is the state and condition of the shuttle that the umpire actually sees on which he makes his decision, not complaints from the players. From all the videos the umpire simply waves TH away after checking, apparently satisfied that there was nothing wrong.