process substitution stdout connected to pipeline

[Pádraig Brady]

zsh behaves as I expected:
% : | tee >(md5sum) | sha1sum
da39a3ee5e6b4b0d3255bfef95601890afd80709  -
d41d8cd98f00b204e9800998ecf8427e  -

bash though seems to connect the stdout of the process substitution
to the pipeline, which seems like a bug:
$ : | tee >(md5sum) | sha1sum
253a7a49edee354f35b2e416554127cf29c85724  -


cheers,
Pádraig