Sorry, maybe my comment wasn't quite clear enough.
BitKeeper license problems caused him to look for another VCS. However, before he started git, he tried a bunch of other DVCS systems, including open source ones, and decided he couldn't work with them because they were simply too slow. Hence git. See http://en.wikipedia.org/wiki/Git_(software)#Early_history From the quote there it's clear that it's not a BK rewrite. git is apparently faster than BK.
BitKeeper license problems caused him to look for another VCS. However, before he started git, he tried a bunch of other DVCS systems, including open source ones, and decided he couldn't work with them because they were simply too slow. Hence git. See http://en.wikipedia.org/wiki/Git_(software)#Early_history From the quote there it's clear that it's not a BK rewrite. git is apparently faster than BK.