[comex]

Are you sure it's handwritten or obfuscated?

I remember from when I used to disassemble compiled ARM code (not on the NDS though) that it was common to see CMP, followed by a bunch of instructions with one condition predicate, followed by a bunch of instructions with the opposite predicate.

In this case, it's subtly wrong to use that pattern, but only on older versions of ARM. That could reflect a very sneaky attempt to break emulators… but it could also just be a compiler bug.

That said, I too don't understand how corruption could be produced unless there was a copy/paste mistake.