From a pragmatic perspective: Berkeley Systems went through a long chain of acquisitions in the late 90s/early 2000s and eventually ended up under Vivendi, which hasn't done anything significant with the rights since a Flying Toasters themed J2ME game [1] in 2006. I doubt very much that they're going to do anything.
This is pretty well trod legally. By the user taking a specific action, it makes the user responsible. Comma.ai uses the same technique. Technically their self driving hardware comes with no software. You have to click a button and point it at their GitHub to get the software on it, but it's automatic after that.