I have noticed that sometime test complete script fails to execute complete scripts and log the results with Zero Warnings and Errors reason could be any but result is incomplete execution of script....
Honestly, doesn't matter... if you're properly logging errors and/or warnings when something doesn't work properly, the number of checkpoints passed should equal "all" if there are no errors or warnings. But the fact that you state that there is a possibility of a script failing but not logging an error means that your script is failing with no evidence of the failure. Again, I would rearchitect to make sure you log errors or warnings when the script does not run properly. If it's done properly, those errors and warnings should be sufficient to tell you what you need to know.