Earlier quoted context omitted.
Just translating would probably leave it as a "derivative work". However, note that licenses like the BSD and MIT licenses came specifically from universities releasing their code under very permissive terms. Perhaps your university can be convinced to do the same.
How many universities have ever given a startup trouble for making software that was a "derivative work," though? Not one that I know of. In practice it's enough to rewrite under conditions where no one has claim to your IP.
I think the point that you're getting at, and I wholeheartedly agree, is that if you understand how something works in and out that rewriting it isn't a big challenge.