Murray,
this looks even worse. For example the first 70 characters are:
IFJFKEKGLFKGLHLHLGKHKGKFJGJGLGIFIFJFJGIGJFJFKFKFIGJGJGIFKFIFIFJFJFJEIF
Normally it is something like
II* ► CR☻ ♦æ ☼ ☺♥ ☺ É• ☺☺♥ ☺ ◘♣ ☻☺♥ ♥ ╩ ♥☺♥ ☺ ♠ ☼☺☻
I don't think it would be useful to go into details, but the file does not resemble anything like a TIFF (the CR2 files are TIFFs). It does not look like compressed either (I don't mean the original raw image data compression but a file compression carried out by the disk driver or firmware).
I have no experience with RAIDs. My unfounded guess is, that the data has never been written on the disk, but I suggest you to seek for advice from those, who know about RAIDs.
I'm sorry for the trouble, I can't help you.