In this paper we describe results from an exploratory study observing infusion pump use in practice. From 31 observations of pump programming we note 10 low-level disturbances, which we conceptualise in terms of unremarkable error. This data supports a view that well performing systems cope with error as part of their normal work. Users are able to recover from error and are resilient to performance deviations. However, it is not clear how we, as HCI researchers, should respond to these minor errors: should we aim to minimise them or instead aim to improve detection, recovery and control in safety-critical systems? What is clear is that without remarking on unremarkable error we cannot begin this dialogue and consider the handling of these issues. To conclude we recognise four important factors that influence remedial action, and we highlight the need for a socio-technical approach for making change that is appropriate for practice.