Despite a growing concern with ethics in sociotechnical studies with/for older people (aged 65+), we still lack an exploration of strategies to identify and tackle potential negative effects that can emerge during and after the research. This is particularly critical when working with frail participants, vulnerable groups, or sensitive settings. How can we ensure that the technology we develop and/or evaluate does not harmfully impact our research participants, even if unintentionally? Drawing on a case study of a communication app developed to address loneliness and social isolation in later life, as well as on years of ethnographic fieldwork with older people, we argue for an ethical display approach. This approach: i) bridges procedural and situational ethics, ii) engages ethics throughout the research process, and iii) maps both positive and negative 'unintended consequences', applying Robert K. Merton's sociological framework.