Tarzan,
Well, first of all, it's not as simplistic as you're implying. For one thing, CSCO would be legally liable for blatantly mis-stating reality. If the CEO says, we are not interested in acquiring Ciena, and have not talked with them about merger, then he puts his company at huge legal liability if they turn around and do it anyway. We're talking major law suit that they would almost certainly lose.
Clearly, if CSCO had any interest in Ciena, they would have skirted the issue, like TLAB did. Don't deny or confirm. No legal obligations that way. What CSCO did was to clearly state that they are not interested. Could change in a year or two, but for now, no dice.
-John |