Travis does not accumulate exit codes for construction

Question

I have the following .travis.yml:

sudo: required
language: node_js
branches:
  only:
    - master
before_install:
  - curl https://install.meteor.com | /bin/sh
  - npm install standard -g
script:
  - standard
  - sh run_tests.sh
  - '[ "${TRAVIS_PULL_REQUEST}" != "false" ] && bash check_for_new_version_number.bash'
  - '[ "${TRAVIS_PULL_REQUEST}" = "false" ] && printf $LI | meteor login && meteor publish || exit 0'

If any of the build commands fails (exit code! = 0), the assembly is still marked successful, since the last command exists from 0. If I changed the last command to exit from 1, the assembly will fail.

According to http://docs.travis-ci.com/user/customizing-the-build/#Customizing-the-Build-Step , these exit codes must accumulate, and the assembly should fail if there is any failure. What am I missing?

Thank!