Use a more strict content pattern in error sweep

(cherry picked from commit 8c007d9ff9180ec1e3f5ab1f8e8e8751c7e7ede0)
Signed-off-by: Alex Nelson <a.nelson@prometheuscomputing.com>

Conflicts:
	src/do_difference_workflow.sh

(cherry picked from commit 3bcf4d16115d276262ac0787de29a4f3e96dc0e5)
Signed-off-by: Alex Nelson <a.nelson@prometheuscomputing.com>