In California Highway Patrol v. Superior Court (Allende) (2006) 135 Cal.App.4th 488, the issue was which costs could be recovered under Government Code section 53150. The County and the League of California Cities filed an amicus curiae brief in Allende in which they argued that emergency response costs were recoverable even when there had been no incident requiring an emergency response. In Allende, supra, 135 Cal.App.4th 488, real party in interest Allende caused a car accident while he was under the influence of alcohol. (Allende, at p. 493.) After the California Highway Patrol (CHP) billed Allende for various expenses in responding to the accident, he brought a class action complaint, which alleged, among other things, that the CHP could not charge him for some of these services under Government Code section 53150. (Allende, at pp. 493-494.) The trial court ruled in favor of Allende, and the CHP brought a petition for writ of mandate. (Allende, at p. 495.) The County and the League of California Cities then sought to file an amicus curiae brief in the reviewing court, arguing that the court's analysis would not be "complete" unless it considered "what constitutes an 'incident' triggering a public agency's right to seek reimbursement of costs under section 53150." (Allende, at pp. 495-496.) The reviewing court granted the request, but rejected the County's argument that "an arrest for driving under the influence of alcohol or drugs qualifies as an 'incident,' regardless of whether the driver causes an accident." (Allende, at pp. 496, 498-502.) The Allende court then held that the trial court had erred in its determination as to which costs the CHP was entitled to recover under Government Code section 53150, and granted the peremptory writ of mandate. (Allende, at pp. 502-509.)