In Déjame Que Te Cuente by Jorge Bucay, why would the subjunctive be used when he says "haya tardado"?
-Sí, claro. ¿Qué te ha pasado? ¿Por qué has tardado tanto? ¿Te has perdido?
-No, no es que haya tardado. No he querido llamar al timbre para no molestar, por si estaba atendiendo a alguien...
Can any event that didn't happen use subjunctive and would the meaning be identical if the indicative was used?
I found another example where an event that didn't happen uses the subjunctive (from Historia de un Gaviota by Luis Sepúlveda): "En ninguna parte está escrito que los gatos entren gratis."