The tone, length, diction, and specifics of the apology will depend on the rhetorical situation (author, purpose, audience, context). If you think the statement should be given verbally, you can specify that you are authoring a transcript of verbal remarks. 

Along with this statement, you will write a rhetorical addendum. In this addendum you will provide appropriate background, and explain why you chose this incident. Then, describe the choices you made as a writer and why they are appropriate to the situation, what you learned from this project, and highlight any connections to other course readings, discussions, etc.

In your rhetorical addendum you will use the facts of the case to explain why the choices you made as an author are rhetorically sound. In this way, it is more argumentative than your rhetorical analysis was. However, a good rhetorical addendum will also discuss the process of coming to these decisions, or concede possible faults or adverse audience response. Exemplary addendums will compare their case study to similar events, and cite sources so the reader can learn more.