Some further info I got while using IE8's debug function for the first code snippet:
thisWeb was having the value of "https://mydomain.sharepoint.com"
thisUserDisp.status = 200
thisUserDisp.statustext = "OK"
thisUserDisp.readyState = 4
thisUserDisp.responseText = "" (This was literally a blank field)
thisField = ""
It's probably because the responseText is showing blank. But I could go to https://mydomain.sharepoint.com/_layouts/userdisp.aspx?Force=true directly and see all the details...
thisWeb was having the value of "https://mydomain.sharepoint.com"
thisUserDisp.status = 200
thisUserDisp.statustext = "OK"
thisUserDisp.readyState = 4
thisUserDisp.responseText = "" (This was literally a blank field)
thisField = ""
It's probably because the responseText is showing blank. But I could go to https://mydomain.sharepoint.com/_layouts/userdisp.aspx?Force=true directly and see all the details...