My understanding is that Unix V8-V10 were not full
distributions but
patches.
"Patch" connotes individually distributed small fixes, not complete
working systems. I don't believe Brendan meant that v8 was only a patch on
v7, but that's the natural interpretation of the statement.
V8-v10 were snapshots, yes, possibly not perfectly in sync with the
printed editions. But this was typical of Research editions, and especially
of Volujme 2,
which was originally called something like "Documents for Use with Unix".
Doug