Ah ha! So the corrupted RAW file idea wasn’t so far off after all! 🙂 Glad you found a solution, and hope that it sticks!
I have seen an instance where a relative of mine moved several hundred .jpg pictures from an SD card to a laptop HDD, then to an external HDD and in the process about 75% of them were corrupted. They had pink/green lines and tints all over them, a real mess! We were very disappointed, and tried to diagnose the problem, but there wasn’t really any evidence to work with. Some time later, I just happened to be looking through this person’s Recycle Bin, and happened to find a folder full of the original photos that weren’t corrupted! Evidently what happened, was that the photos came off the card OK, and became corrupted when transferred to the external HDD. The originals were then unsuspectingly deleted, since they were “all safe” on the external hard drive… 🙂 Thankfully, I could restore them with the click of a mouse button, and all was well!
So learn a lesson, NEVER EVER delete your original files until you’re sure that the copies are safe and intact. Also learn that occasionally USB connections are susceptible to damage, and strange things might result, so if in doubt, try a different connection.