For me, the key point is that Adama says "Tactically, she did nothing wrong." As an earlier poster pointed out, tactics win battles, strategy wins wars. Sometimes being willing to lose a battle that can be won but isn't worth winning is what allows you to win the war. Cain was too interested in being ready for the next battle.
In this case, the ultimate 'war' was the survival of the Colonial species, and abandoning civilians or raiding them for supplies was the wrong strategic call unless there was no chance of preserving them (but of course, to quote Adama's success in preserving his fleet as proof that there was invokes 20-20 hindsight, so it doesn't prove that she was wrong to take the decision under the circumstances).
I agree with the bolded, but disagree with the rest. Consider waging a guerrilla war (many examples throughout history where a small guerrilla force has beat back a superpower) and fighting for your home vs. a pilgrimage to a mythical planet. In hindsight the choice might be wrong, but in reality the first choice is the more rational option that most people will take and many have previously succeeded in. Thus, you have to judge her based on that. And Adama's quote seems to say that her tactics were flawless in waging that strategy.