My understanding (direct from Graydon, some 18 years ago) was that Linus admired Monotone except for its slowness. Graydon liked making things correct then fast, but was on a break in Köln when Linus (provoked by loss of BitKeeper) emailed on Friday endorsing Monotone's design and asking for speed. Graydon said "let me buy a laptop and I'll start on Monday".

Monday rolled around and Linus said "too late, I wrote it already" (it => git).