[opendmarc-users] p=quarantine when RejectFailures false?

[postfix at ptld.com]

My relevant config:

    IgnoreAuthenticatedClients true
    RequiredHeaders true
    SPFIgnoreResults true
    SPFSelfValidate true
    RejectFailures false
    RejectMultiValueFrom true

I found an email living in postfix mailq quarantine because it failed 
dmarc and that domain had a p=quarantine policy. But my config has 
RejectFailures false which my understanding is it shouldn't reject any 
mail but just add the headers. Why was this email physically quarantined 
and how do i stop it from happening again?