I'm sure you're right; it means what West says. "Desinteresar" creditors in Argentina means paying them what they are owed, and by extension it evidently means satisfying claims of other kinds.
Here's a relevant example: an agreement between a university faculty and a municipality, whereby the former provides teaching staff and the latter service personnel. It says that each party will fulfil its responsibilities as employer and hold the other party harmless from claims of its own employees against the other party. So in the case of service personnel the municipality "[se obliga] a desinteresar a cualquier persona de su dependencia, que llevare adelante un reclamo laboral contra la Facultad". See clauses 4-5 on p. 3
http://digesto.uncu.edu.ar/documentos/digesto/2015/03/R_RE_0...