Usually ‘Media Needs to Be Restored’ is a file system check. It will happen if you lose power or put any unregistered/foreign files into any of the directories. The most common cause of these are:
1) Browsing the card in Mac OS, which puts 1k temp files in every folder it sees. This will cause a Restore prompt to appear every time you power on until the card is reformatted.
2) Exporting clips from FCP or other editors that do not create EX metadata on export and just send raw .mp4s to CLPR
3) Loss of power or other data-related hiccups which may cause the camera to want to verify the contents of the card/directories
If you actually lose power during recording in most cases you only lose what’s in the camera’s internal buffer. (The camera writes to a buffer first then pushes to the card every few seconds.) A salvage file is created on the media which lets the camera know that a file was not closed correctly. After re-powering a prompt to execute a ‘Salvage’ should appear. You should always confirm/accept and perform the salvage– there is no way to execute manually. At this point the camera reads the Salvage file and attempts to properly close the file that was recording during the power loss.