OR = (1,244/250)/(1,231/305) = 1.23
Now, your effect estimates have been attenuated (i.e., biased towards the null). Again, this makes sense because you have increased your 'c' cell (D+E-) thereby increasing the denominator of your estimates. Like Scenario #1, you misclassified exposure to lawn/garden pesticides only among individuals with breast cancer. Because your misclassification is linked to disease status, this too is an example of differential misclassification in which the effect estimate was biased towards the null.