It's an unimportant distinction for the purposes of this discussion.
Under the law, damages have occurred, especially if someone then takes that source code and makes it public.
So whether you have 2 copies or 1 copy or umpteen copies, if you've economically affected someone, you will lose that fight in court.
But this is not relevant to this discussion and I think we should keep on topic.
The point is this:
Dylan16807 is just trying to rationalize something that he wants, which is for the source code to be public.
It doesn't matter how IP differs from owning a house. It doesn't matter if it can be copied (and thank you for having the arrogance to explain that on board full of developers, btw...).
None of this matters. What matters is that Blizzard paid for the creation of the code, and they're afforded protections under the law.