Good faith communications are essential. And not just “so we can sleep at night.” It’s practical and efficient and productive and makes sure everybody is enough on the same page enough to accomplish a goal. Without good faith communications, work and projects become increasingly untenable as the a spiral of CYA overhead gradually expands.

As for buying time…why buy it at the cost of your credibility? If the situation is that dire that it is unacceptable to say something like, “I need 4 or 12 or 24 hrs to touch base with implementers and stakeholders so I can give you an accurate, detailed answer,” it’s time for a “come to the mountain” discussion anyways. And if you think you’re not at that point, you haven’t been statusing honestly with yourself even.

The practical reality that folks even with the best of intentions behave as if these issues are flexible enough for fudging that euphemistically gets called “spin” is what makes managing the communication in a group or project as challenging as accomplishing any set of business or technical goals.

I try to be as honest as I can. Is omission of information considered lying? Not necessarily. I think it depends on the situation and the amount of information withheld.
The factors that contribute to my level of honesty are determined by the person I am dealing with and, like Scott mentioned earlier, how I perceive that person will react to the information provided.