Bug in Set-ADAccountPassword cmdlet by Baterias

I have two Active Directory environment: production.mycompany.com and development.mycompany.com. I must change passwords on all employees in development environment. I tried this command:

Get-ADUser -filter * -SearchBase "ou=employees,dc=development,dc=mycompany,dc=com" -Server dc.development.mycompany.com|%{Set-ADAccountPassword $_.samaccountname -reset -NewPassword $pass -Credential $Adm -WhatIf}

This command has an serius error: credential $Adm belongs production environment. But no problem,-whatif parameter prevents damages in domain accounts.

Horror! -whatif parameter doesn't work in Set-ADAccountPassword cmdlet. My employees lost them passwords.

This is a serius bug in activedirectory module.