In older iPhones, the ‘file system dirty’ flag indicates unclean device shutdown, which affects the ability to perform bootloader-level extractions of Apple devices running legacy versions of iOS (prior to iOS 10.3 released in March 2017). As such, the “file system dirty” flag must be cleared before the extraction. In this article we discuss the very different forensic implications of this flag if it is set on the Data or System partitions.