In the paper titled "A Note on Comparative Ambiguity Aversion and Justifiability" - Battigalli et al. (2014), we show that higher ambiguity aversion expands the set of self confirming equilibria of a game. In this work we show that higher ambiguity aversion enlarges the set of actions justifiable by prior beliefs in any given set, which implies that it also enlarges the set of rationalizable actions of a game. We derive this result from a generalization of the duality lemma of Pearce (1984).