I was able to redeem myself by tracking down and fixing a very difficult transient bug having to do with requests expecting a 100-Continue followed by other pipelined requests. Isolating the problem took two full days, and Sebastian commented over IRC that it doesn't get much more complicated than this, protocol-wise. Anyway, so my tally for the week is:
problem with duplicate start line on 100-continued request with a
5-second delay problem when pipelining two requests, the second
of which includes an Expect 100-Continue;
allow applications to override the default continue handler.