I think comparing the watermark in a PDF manual to the SimCity fiasco is stretching things to say the least.
Personally, I think, like many corporations, Canon will have somewhere a policy that says "If it wasn't printed by us, it needs to be identified as such". For a place as large as Canon, have one policy will be much simpler and lead to less mistakes - I imagine they'd rather have the word "Copy" on their manuals than miss it on an important contract and have trouble.