Which is why people behave that way in airplane cockpits and the bridges of submarines. (Actually, such behavior has gotten people killed in those contexts.)

If someone is insisting on an implicit level of signalling, they can be just as guilty of insisting foolishly as someone insisting on the explicit level. When implicit communications are demanded for 1) a higher stakes situation on the basis of 2) the supposed potential victim status of one party -- something is way out of whack. Not only is the safety of clear communications being abrogated, the danger being borne is skewed to just one party.

Beyond the level of the social white lie, if you're advocating deniability to "be safe" you're probably doing something dishonest on some level. Extending the mechanism of the social white lie to a situation where more is at stake is just foolish.