The size gives it awayA thumbnail JPEG rides within every NEF, CR3 and ARW, put there so the camera has something for its rear screen. An everyday tool grabs that, logs the RAW as recovered, and moves along. Which is how a 50MB frame comes home weighing 5MB.
Large files rarely sit in one pieceFree space long enough to hold a big file in one piece is rare on a card. A basic carver halts at the first gap, and that costs you the corner of a JPEG but all of a RAW or a clip. Where the pieces go, and in what order, is written into the file format itself; reading that is where the difference lies.
Every RAW format breaks differentlyTIFF sits under CR2, and that is why it survives damage tolerably. CR3 moved to a newer container with different rules. NEF damage generally turns up as green and purple bands across a frame. ORF, RAF, RW2, ARW and DNG all want their own handling, and no one program off a shelf manages the set.
What a deletion actually removesDeleting on FAT or exFAT frees the cluster chain a file was using; formatting frees all of them at once. Nothing is wiped from the card, which is exactly why recovery works — and exactly why your next exposure may land on the picture you wanted.