The bash pipefail option merely determines the source of the return value of a pipeline
in the event of an error. Changing the option will not change the observed behaviour.
Based on your description of the problem,
it sounds like the 'e' option has been set
and you want to unset it.
If it is set in your script,
use 'set +e' to ignore errors and
'set -e' to re-enable the exit on error behaviour.
If it is set in the sourced script, you'll need
to change it there or resort to other trickery.
-Gyepi