JScript.NET: Enumerating WMI collections

In JScript.NET the following snippet:

wmi.js
------
var wmi  = GetObject("winmgmts:{impersonationLevel=impersonate}!\\\\.\\root\\cimv2"),
    col =null, prc=null;
col=wmi.ExecQuery("SELECT * From Win32_Process", "WQL", 32);
//col=wmi.InstancesOf("Win32_Process");
var e = new Enumerator(col);
for (; !e.atEnd(); e.moveNext()){
  prc = e.item();
  print(prc.CommandLine);
}

compiles with:

%windir%\Microsoft.NET\Framework64\v4.0.30319\jsc.exe /platform:x64 wmi.js

and executes, but changing the WMI call with:

col=wmi.ExecQuery("SELECT * From Win32_Process", "WQL", 32);

compilation still works, while the execution gives the:

Unhandled Exception: System.InvalidCastException: 
Unable to cast COM object of type 'System.__ComObject' to interface type 'System.Collections.IEnumerable'. 
This operation failed because the QueryInterface call on the COM component for the interface with IID '{496B0ABE-CDEE-11D3-88E8-00902754C43A}' failed due to the following error: 
'No such interface supported (Exception from HRESULT: 0x80004002                        

I don't understand why, since for both InstancesOf and ExecQuery documentation says:

If successful, the method returns an SWbemObjectSet

Also, WSH JScript can enumerate both InstancesOf collection and ExecQuery.

First things first, remove the flag for wbemFlagForwardOnly and the ExecQuery returns an object that works as expected.

var wmi  = GetObject("winmgmts:{impersonationLevel=impersonate}!\\\\.\\root\\cimv2")
   , col =null, prc=null;

col=wmi.ExecQuery("SELECT * From Win32_Process");
//col=wmi.InstancesOf("Win32_Process");

var e = new Enumerator(col);
for (; !e.atEnd(); e.moveNext()){
  prc = e.item();
  print(prc.CommandLine);
}

For the explanation, here's a shot in the dark (I don't work with Jscript.NET every day nor am I an expert).

from https://msdn.microsoft.com/en-us/library/ms974547.aspx:

"A forward-only enumerator performs much faster than the default enumerator, because WMI doesn't maintain references to objects in the SWbemObjectSet"

from the error:

"Unable to cast COM object of type 'System.__ComObject' to interface type 'System.Collections.IEnumerable."

It seems that converting collection to enumerator requires a reference to the object being casted. With wbemFlagForwardOnly flag, there is no reference passed so cast fails.

That is how I read this. Take it for what it's worth.

An interesting thing I found when researching: there is no error with this enumerator using wscript/cscript versus executing exe from jsc/csc.

Also, it seems VBScript has no problem enumerating with these flags; check out the examples and compare - https://msdn.microsoft.com/en-us/library/ms525775(v=vs.90).aspx.