While texts and still images are foundationally used to evidence qualitative findings, they often require significant interpretations from the reader to extract meaning. In this study, we explored alternative ways of evidencing qualitative findings, with a particular focus on how video can support the warranting of interpretive claims. We used an investigation of generative artificial intelligence (GenAI) affordances in argumentative writing as a context to examine how video-based representations could reveal insights that might be obscured in texts or static images. We conducted case studies in which we observed and interviewed participants as they used GenAI tools in their writing. Drawing on theoretical lenses of mediated action and quantitative ethnography, we identified affordances through an ethnographic content analysis of screen recordings and transcripts. We proposed three dimensions—temporal, spatial, and contextual—to guide the use of video in capturing and analysing human-tool interactions, with particular attention to how mediated actions co-occur within meaningful stanzas. Using a multimodal narrative that combined texts, still images, and looped video clips, we showed how these dimensions reveal tool-use patterns often obscured in traditional qualitative representations. Our contribution is both theoretical and methodological: we explain why video matters in warranting qualitative findings and demonstrate when and how it can uncover mediated actions emerging through time, space, and context—and, critically, how these actions relate to one another in stanzas.