> Stepping back, though, one could still ask the question; what's the risk of a Java developer accidentally getting some OpenJDK code a little too closely? There's an order of magnitude difference between even a smaller AGPL developer and Oracle.

It would be extremely interesting to know how much accidental and non accidental code infringement happens and in what proportion of those cases go to the courts. I would guess that both cases happen utterly constantly and it is only a tiny minority of those cases where legal action is taken. If that's the case right now, then nothing has changed with this tool except the possibility of playing hot potato with liability when those few cases that do happen make it to courts. Even if the developer actually wrote the code that infringed, copilot could make a useful scapegoat and every case will have plausible deniability if copilot lacks really good explainability.