Test step fail then pass, test case is status fail

Hmm..strange really that security fails inconsistently.
1. Have you check in your application logs if the request is hitting server and getting security failed response in the first place? Becuase, it could be an application defect as well.
2. Coming to the actual question, are you using assert in groovy step to check the previous step response before re-running? If so, that could be the culprit for making the test case failed. Instead of assert, try using if condition.