Well there's two arguments to be made. They 100% gave him the source code in a grab bag of goodies. That's a pretty simple case of he has a right to the disc itself, so he could have just kept it (or resold it) and not published. Them giving him "stuff" was them "buying" the item back, not just them being nice (as you put it).
There's also an argument to be made that the code itself does not infringe on their IP, as this was the lost source code from the old edition of StarCraft (from how I'm reading it in the news). Losing this code specifically made Blizzard restart the project, so it's not even the same project nor a commercially released product.
The former argument is pretty black and white. The latter very tenuous.
> There's also an argument to be made that the code itself does not infringe on their IP,
That’s not how IP works.
Blizzard didn’t forfeit their rights to the IP at any point. Even selling them a grab bag of stuff that unintentionally included a copy of the source code doesn’t mean the recipient actually received a legal license to the IP.
You can make all the arguments you want, but in the court of law you’re not going to get away with anything that involves giving away another company’s IP, even if they accidentally let you see a copy of it. “Finders keepers” doesn’t work with IP.
Sure, the recipient doesn't have the right to call it their own or commercially distribute/benefit from it. I didn't make a claim otherwise.
I said the code they have does not infringe on the commercially released product called StarCraft as it is not a portion thereof. I even stated that releasing it or otherwise making it available is tenuous at best. So I'm not even sure what you're arguing.
> “Finders keepers” doesn’t work with IP.
He didn't "find" it, they willingly transferred it to him along with a bunch of other things they randomly grabbed from their warehouse.
"IP" is a collection of various laws and contracts used to keep exclusivity, it doesn't exist on its own. No law mentions IP. I am not sure the case is a firm as you say it is. Especially since he didn't sign anything.
There's also an argument to be made that the code itself does not infringe on their IP, as this was the lost source code from the old edition of StarCraft (from how I'm reading it in the news). Losing this code specifically made Blizzard restart the project, so it's not even the same project nor a commercially released product.
The former argument is pretty black and white. The latter very tenuous.