Weird… the CR2 header(*) can be found deep down in the file (after about 20M of data):
Of course one can copy the tail of the file (from the TIFF II* marker to the end), but this makes a RAW files of 2.5MB, a bit small for the output of a 700D.
This looks like a filesystem corruption. If the disk hasn’t bee tinkered with, the rest of the data could possibly be in the sectors following those of the end of the file, but in the general case they could be anywhere, in one or more pieces, with some pieces already overwritten by later disk activity.
(*) In truth, not the file header but a file header. Maybe the data the owner is looking for is what is before that header, and is missing its header, which could be somewhere else on the disk, and perhaps have been included at the tail of another file. But looking for this would require a dump of the whole media.