I was always under the impression Monotone - which was released two years before Mercurial - was the inspiration for git, and that this was pretty well known.
This is all fairly speculative, but I didn't get the impression that Monotone was a main inspiration for Git. I think BitKeeper was, in that it was a tool that Linus actually liked using. Monotone had the content addressable system, which was clearly an inspiration, but that's the only thing I've seen Linus reference from Monotone. He tried using it and bailed because it was slow, but took the one idea that he found interesting and built a very different thing with that concept as one part of it is how I would interpret the history between these projects.
Linus was definitely aware of and mentioned Monotone. But to call it an inspiration might be too far. Content Addressable Stores were around a long time before that, mostly for backup purposes afaik. See Plan9's Venti file system.
Yes, Monotone partly inspired both. You can see that both hash contents. But both git and hg were intended to replace Bitkeeper. Mercurial is even named after Larry McVoy, who changed his mind. He was, you know, mercurial in his moods.
