– Not legal advice-- If you have evidence that it got scrapped for good, even if it’s copyright infringement, they can’t claim any damages. They, at best, can DMCA GitHub, but you’re VERY unlikely to get sentenced guilty in a trial (in the event of one, which won’t ever happen because they know).
–Not legal advice-- Except they can’t do clean-room development because copyright is viral. If they had access to the copyrighted source, any code they write on the matter, if it coincides with the copyrighted one to some extent, can be pursued for copyright claims (IBM v. Microsoft). For example, when there’s a leak of Windows source, ReactOS devs get super scared, because it really puts them on the line. Another example is Nouveau, which can’t accept anyone who has worked at NVIDIA. That being said, the company was not intending to do anything with it, so they can’t claim damages; ergo, OP is completely safe.
Fixed.