[PowerCLI] Remove-USBDevice tries to remove both the Host USB device and the USB controller

I have a user who has permission to Host USB Devices, when I try to call Remove-USBDevice from this user I get an error:

PS C:\> Get-UsbDevice $vm | Remove-USBDevice -Confirm:$false

Remove-UsbDevice : 9/12/2013 8:08:30 PM    Remove-UsbDevice        Permission to perform this operation was denied.

If I give the user permission to be able to remove devices then this call succeeds and also removes the "USB Controller". So it seems this call removes the USB storage device and also the USB Controller.

Is this expected behavior of the api "Remove-USBDevice"?

I'm on vSphere 5.1 connected to vCenter 5.1 and using the latest PowerCLI.