We discuss two philosophical explanations of the epistemic side-effect effect: the doxastic heuristic account (Alfano et al. The Monist 95 (2): 264–289, 2012) and the consequence account (Paprzycka-Hausman Synthese 197: 5457–5490, 2020). We argue that the doxastic heuristic account has problems with explaining knowledge attributions in cases where the probability that the side effect will occur is low and where the side effect does not ultimately occur. It can explain why there is a difference between the harm and the help (...) cases but it cannot explain why people are willing to attribute knowledge in the harm cases. Such attributions can be explained on the consequence account, which takes knowledge attributions in norm-violation cases to be due to the increased salience of a consequence-awareness claim (knowledge that a possible consequence of the chairman’s action is that the environment would be harmed). We report the results of a new study that tests the predictions of both accounts. In some conditions, people attribute knowledge of the side effect even in cases where the chairman does not have the relevant belief. This result directly contradicts the central tenet of the doxastic heuristic account. Linear regression models of knowledge attribution that correspond to the two accounts were compared. The addition of different justification options significantly contributes to the predictive power of the statistical model. The consequence account can explain the pattern of justifications better than the doxastic heuristic account. Our findings support the consequence account and pose a challenge to the proponents of the doxastic heuristic account. (shrink)