An important instruction should not depend on someone noticing a casual aside.

Mentioned in passing is not the same as told. When something matters, saying it lightly protects you more than it protects them, because if it goes wrong you can point out that you did mention it. An aside competes with everything else in the room, and people filter for weight. Importance has to be marked, not merely included.

Look at what you handed off recently and ask which key detail travelled inside a half sentence. Say it again on its own, in writing if it matters, and check that it landed.