Engineers tend to be too people-pleasing. When someone from management asks "can you scan devices for CSAM without violating privacy?" the answer should not be "hmm... well... maybe if we did it this way it could work". The answer you should give us "no" or to hedge your bets "I don't think so". Same to the government and the court. In particular a court isn't asking for a statement of objective reality whether it's possible, they're asking whether you think you could do it.