This paper explores the ways in which apology functions as a stance act at public speech events. Rather than focusing on speakers' intentions, in this study I pay attention to indexical meanings associated with apologies in a specific context. The study primarily analyses apology sequences that involve code-switching, which were drawn from ethnographic data gathered in a Korean university where English has been adopted as its official language (EOL). Data analysis shows that the use of apology allows speakers to take a stance towards their language choice and the institutional language policy. Both apology and speakers' metalinguistic articulations prior to code-switching reflect and reinforce the two language ideologies: (1) the language policy is intended to serve for international members of the university, and (2), Korean can be used when needed. A closer look at the way in which apology is used in specific contexts suggests that speakers' main purpose of apology is self-presentation in a public event. Apology functions to index speaker's defiance of an institution's language policy while avoiding their responsibility for the action. The sociolinguistic concept of stance allows us to better understand speakers' positioning with respect to norms and expectations informed by institutional language policy.