I'm not an EV expert to answer this but I will say that limit and NL are much different in that its correct in limit to bet but that bet size can't be modified so its at least easier for both people to be right. In NL, because someone can bet all their chips at any time, it may not be possible to both be right but at least its much harder. If someone is betting their hand to protect it but giving proper odds for a flush chaser, then one guy is wrong and one is right. It would seem by just logical sense that both people can't be right, but that is also assuming that both people can properly calculate implied odds and know exactly how much they will get paid off if they hit and such.

I guess it depends on what you mean by 'right'. If you just mean profitable - yes, both players will make 'some' money in this situation. If you mean optimal - usually not, the guy with the made hand is not maximizing his profit (barring strategic reasons for underbetting the pot).

Interestingly, when playing against several oppponents, you sometimes want people to play correctly. Their mistakes can cost you money, ridiculous as that sounds. You can read Morton's Theorem here:

http://www.concours.org/andymorton/andy ... 0Part%20II