You've asked the following:
> Can you point to a case where a coding assistant has done so that would constitute copyright infringement?
The talk provides a couple of examples that are blatant.
Now you are arguing that a snippet of code might not qualify for copyright. This is irrelevant to the question you asked because that snippet is part of a larger codebase which is covered under a license. Copying lines of code that are small enough does not eliminate copyright.
If you really want to go down the route of snippets not qualifying for copyright then this entire discussion becomes pointless. By that logic nothing is copyrightable because it is just "a couple of lines of code."
Try that with the leaked source code for Windows XP for example. Bet that will land one in hot water very quickly.