This study extends the rhetorical arena approach to crisis communication with an argumentative perspective. A rhetorical activity in which reasons are communicated to justify and obtain acceptance for a claim, argumentation plays a crucial role in (re)legitimizing corporate trustworthiness following a crisis episode. Arguments supporting or rejecting trust claims do not only pervade the corporate crisis response message (e.g., an apology), but also the public reactions in the rhetorical arena, i.e., the multivocal conversational space that opens up in a crisis context. Therefore, rhetorical arena crisis communication takes the form of an argumentative polylogue in which corporate trustworthiness features as the main issue. We develop a method for the analysis of trust-related polylogues occurring in rhetorical (sub-)arenas. Unlike existing methods, like tone analysis of online comments, our approach enables to examine, more specifically, the reasons organizations and stakeholders present for or against trust. This, in turn, provides an enhanced method to assess the effectiveness of a crisis response strategy. In order to illustrate our approach, we elaborate a case study based on an apologetic article published by Facebook CEO Mark Zuckerberg and a sample of public reactions appearing on media articles and on subsequent online discussion websites.