Are those mutually exclusive? If you don’t have a medical certificate, you cannot engage in operations requiring one. Does not matter why you were denied.
At the same time you can reapply for a medical certificate when you and the AME believe that such application will be successful.
I don’t believe the case of being denied a medical certificate for a medical reason and then flying an operation under 61.53(b) without a certificate, arguing that one does not have a condition which would prevent safe operation, has ever been adjudicated in an administrative or court case.
I suspect in a really egregious case the FAA might try and argue that the airman should have known due to the denial, but I am not aware of any actual case on this.
One of those corner cases where there is not an exact answer under current regs.
