No one actually ever checked whether it even has the slightest chance to hold up in court. Neither "free" nor "open source" are strict terms in a legal sense,

No one actually ever checked whether it even has the slightest chance to hold up in court. Neither "free" nor "open source" are strict terms in a legal sense, the rest is a non-exhaustive set of examples. It's probably never of any practical issue for the developer, as they don't care enough, but for people that actually have to audit their code bases for legal issues, this thing is a no-go.