Emergency medical services (EMS) clinicians must decide whether to transport patients to hospitals for emergency care, what level of emergency care they require, or to treat the patient at home and not transport to hospital. This analysis focused on patient safety incidents in Swedish prehospital care that occurred after 2015, following implementation of a protocol allowing EMS clinicians to triage patients to see-and-treat (non-conveyance) or see-and-convey elsewhere. Qualitative analysis of incident reports revealed three themes: assessment of patients, guidelines, and environment and organization. EMS clinicians deviated from the protocol in 34% of cases, putting patients at risk of inappropriate triage to see-and-treat.