OK, this reopens and also reports.
#!/bin/sh -eu
#Reopen and report a Debian bug closed by spam, which you feed in via stdin.
bug=$(
perl -nwe 'if (s/^X-Debian-PR-Message: they-closed (\d+)$/$1/){print;exit}')
if test $bug
then
set -x
echo reopen $bug|
mail -s "Reopening $bug closed by spam" control@bugs.debian.org
w3m -dump "http://bugs.debian.org/cgi-bin/bugspam.cgi?bug=$bug;ok=ok";
else echo $0: no bug number found. 1>&2; exit 1
fi