Has to. This is fundamental to data mining. You gotta have a set of "good" results (rank order in this case) in order to tell the machine "find other things that are 'good' like these". I would be shocked to learn they do not also do the reverse for spam: "find other things that 'stink' like these pages". Human input is needed for training the machine what the difference between "good" and "bad" is.
OTOH, if you're saying that Google is using humans to individually tweak rank order for specific queries, then I seriously doubt that happens enough to notice, possibly not at all.