That may be, but it did not stop Apple from then filing rather specious lawsuits over products they claim they invented and then patented.
1. The "Soap Bar " lawsuit: Anything that looked or acted like a mouse was Apple's product and could not be used without royalties paid.
2. The " Colour " screen Lawsuit. Mozaic had also been invented and patented, but again Apple claimed again it was an Apple invention and patent.
There is a historical pattern of this most recently here in Europe regarding Samsung and Apple. It is clear if one wishes to read very long and boring legal transcripts that many Patent Jurists listen to the PR arguments presented in court, rather than actually reading the actual details of the patents themselves. That might be too long and difficult for them to do.
Please do not take this as a crticism of Apple itself, which has clearly revolutionized our world in this Century. If B&O made the naive mistake of not making a patent registration, and Apple then did so later with the IPOD, that is a mistake B&O surely regrets. But it is more than refining an original product or component into a better one, as the Japanese were known for regarding quality.
This is something else when one takes credit and claims royalties in court, for legal patents very strongly documented by other companies and their hard working employees many years before.
One wonders what might have happened to the IPOD if B&O had actually registered and enforced a patent on the wheel control it originally came up with. B&O missed the Ferry on that one sadly, but good for Apple and the IPOD.