> If somebody else had written it and he'd used it, the outcome would have been the same.

IIRC, the mercurial project had already started when Linus started working on Git. (In fact, very early versions of Xen used BitKeeper, following suit with Linux; when the license changed, Xen moved over to mercurial because git wasn't ready yet, and stuck with it for a number of years.)

The main reason Linus wasn't happy with mercurial was the performance -- Linux just has far far more commits and files to deal with than nearly any other project on the planet, and even at the time, operations in mercurial took just a bit too long for Linus.