I don't disagree with your assessment of the law, I just think you (and possibly OP) are looking at issue from the wrong POV. The point of adding a license is not to allow you to initiate legal action, it's to give others some assurance that you won't initiate legal action against them when they use your code.

And while adding a license might get you in trouble, so can not adding one - for example, if the code from that Big Corp is GPL-licensed.