We analyze an intransitive construction involving verbs like Spanish matarse ‘kill’ whose subjects appear to have both internal and external argument properties. Examples include Juan se mató en un accidente de coche ‘Juan got himself killed in a car accident’, in which the subject’s referent shows hybrid behavior between agent and patient as it needs to be engaged in an action leading to its accidental death. We propose that the subject’s internal and external argument properties can be accounted for if subjects can bear two semantic roles by virtue of being associated with more than one distinct head in the syntax (Pineda & Berro 2020). We argue that such intransitive uses involve a distinct argument structure from transitive reflexives despite sharing the same surface form, cf., El sospechoso del homicidio se mató al estar rodeado por la policía ‘The suspect killed himself when he was surrounded by the police’. The present account provides evidence that agents and external arguments do not always correlate since some verb classes can have identical surface form, despite involving underlyingly distinct argument alignment.