This is a clear case of inner barrel of nose cowl (usually carbon fiber) failure. I have seen such a failure on RR engine. It occurs during takeoff thrust when the engine suction is highest. Once a small portion liberates from inner barrel, within no time the rest of the inner barrel and outer barrel fails due high suction produced by fan. On most aircraft it is a turnaround inspection item, to check inner barrel for any surface damage. Engineers are not supposed to stand or sit on the inner barrel for any maintenance work without a protective mat. This is applicable to most modern engines that have carbon fiber honey comb panels in the intake. Just an observation from my experience. Could be other reasons as well,