Yeah, a real browser would produce certain patterns and never certain others. So in some cases one could clearly say it's not a human using a browser. But a scraper could also make efforts to mimic human browsing. Mostly the frequency of requests can tell with high probability tell it's not human. But such algorithms might occasionally give false positives for real users, exactly like it has obviously happened for the archive.

What google service are you referring to? Not sure whether the archove uses any of Google's tracking. I have pretty strong blocking of trackers and ads. But the archive works for me.