Let me give an example, to explain:
* If you receive two applications and the one from someone in category A is better but you choose the one from category B, I presume we both agree that is active discrimination.
* What I'd argue is conscious discrimination but passive is if you e.g. choose to continue to let having graduated from school X count extra much when evaluating candidates, knowing that this will bias your results towards category B and that having graduated from school X has no demonstrable impacts relevant to the job. Whether or not this counts for you I guess may depend on whether you see the individual factoring in of the graduation as an active action or just continuing to passively accept the same discriminatory rules.
* What we'd presumably both agree is not conscious/intentional discrimination is if you choose to make having graduated from school X count more, but you do so you while having no idea that this will happen to bias hiring towards category B.
But in the last case, I'd argue that while we presumably agree it's not discrimination per se, it still perpetuates effects that are likely to be an outcome of discrimination - e.g. chances are the reason it causes a bias is that the school intake is biased.
I'm not saying people are bad for failing to fix every bias like that. I'm saying that someone who claims to care about discrimination ought to at a minimum aspire to paying attention to unexpected biases, ask themselves why, and consider if there are reasonable ways to address it. One way in this hypothetical example would be to examine which factors in the hiring seems to introduce a bias and determine if they actually objectively correlates with improved outcomes or not, as if their only function is to introduce a bias that does not produce better outcomes, they're to me unambiguously discriminatory whether or not that was the original intent.
Personally, I think a whole lot of discriminatory practices falls in this last category - people may not intent do, they just haven't thought through the impact. But some people have thought through the impact and let it stay this way on purpose (e.g. I mentioned in one comment how my ex pointed a situation like this out to her employer and they refused to address it - it was clear it was on purpose)