The first half of both pipes was clearly a copy-pasted
initial logfile processing; the file can be of considerable
size (e.g. several megabytes) so it might be slightly more
efficient and cool (but a bit more arcane) to use bash(1)'s
process substitution along with good ol' tee(1) like this:

$ echo -e '1\n2\n3' |tee /dev/stderr 2> >(grep 2 >STDERR) |grep 1 >STDOUT
$ head STD*
==> STDERR <==
2

==> STDOUT <==
1