While implementing AfterCommandExecuted browser event handler there is a difference between sender and EventsArgs :

private void ActiveBrowser_AfterCommandExecuted(object sender, ArtOfTest.WebAii.EventsArgs.BrowserCommandEventArgs e)
        {
            var browser = (Browser)sender;

            //This returns true when there are frames in the browser
            if (e.Command.HasFrames)
            {

                //This returns the frameInfo in String form for all frames in current browser. 
                Manager.Log.WriteLine("FrameInfo :" + e.Command.FramesInfo);

                //At the same time the 'normal' browser returns a frameCount of zero
                Manager.Log.WriteLine("FrameCount from browser:" + browser.Frames.Count);
               
                           
               
            }
        }

e.Command.HasFrames returns true while browser.FramesCount returns 0

Steps to reproduce:

Download the attached project and run it. The implementation of the event handler is in the very first step.