Last night, I have experienced to disable claims based authentication in SharePoint 2010 using power shell. It can be doable in PowerShell. By using PowerShell script you can shift to claims based or classic mode authentication.
From PowerShell command prompt, type the following script to enable claims based authentication.
$WAName = "http://aspxtutorial.com:82"
$WA = Get-SPWebApplication $WAName
$WA.UseClaimsAuthentication = 1;
$WA.Update()
From PowerShell command prompt, type the following script to disable claims based authentication and convert to classic mode authentication.
$WAName = "http://aspxtutorial.com:82"
$WA = Get-SPWebApplication $WAName
$WA.UseClaimsAuthentication = 0;
$WA.Update()