When is it okay for Senior Leaders to lie or misrepresent the truth?

I think my opinion on the morality of lying would vary with the action from which the lie was derived.

Personally motivated - bad
Protection of others - good

I'm not so much against lying unless it actually negatively affects something (i.e. National Security, etc.). Me personally, I wouldn't necessarily lie, but I would sugar coat the truth, or not say anything at all.

Shutting ones mouth might be a viable alternative.