Repro case for TypeError: Error #1034: Type Coercion failed

test.as

package experimental {
    import flash.display.Sprite;
	
	public class CoercionError extends Sprite {
		
		private var inner:Inner = new Inner();
		
		public function CoercionError() {
			test();
		}
		
		// to separate bytecode
		public function test():void {
			// [Fault] exception, information=TypeError: Error #1034: 
			inner.prop = true;
		}
		
	}

}

class Parent {
	private var _prop:Boolean;
	
	public function set prop(value:Boolean):void {
		this._prop = value;
	}
	
	public function get prop():Boolean {
		return this._prop;
	}
	
}

// required: marked final
final class Inner extends Parent {

	override public function set prop(value:Boolean):void {
		/* this one is optional */
		if (super.prop == value) {
			return;
		}
		/* --------------------*/
		super.prop = value;
	}
	
}