How to check that the backup was successful

I use Powershell to perform backup.
After completion of the Start-WBBackup cmdlet I would like to check whether backup was successful or failed.
Is there any reliable way to find this out?

I tried:
(get-wbjob -Previous 1).Hresult
(Get-WBSummary).LastBackupResultHR

But there was some cases when they did not reveal that last backup was finished with errors or warnings.