"show above" string operations == lines: 95-97, precisely these lines:
   var scrunched = sb.ToString();
   var stripped = scrunched.Substring(0, scrunched.Length - 1);
   var json = string.Format("[{0}]", stripped);

I also cannot get your point, do you mean we don't need StringBuilder at all? Query could return several json objects (body) and we need to prepare json array (let say prepend and append brackets to the concatenation of these bodies), I'm afraid we cannot go without StringBuilder and I think the easiest way to decide whether we have something to deserialize ("if" statement) would be check the StringBuilder.Length property (sorry I cannot see the purpose of mentioned boolean variable).

Any way, thanks for your patience, hope I manage to understand your point soon ;)