http res.on('close') never called for some GET requests

Ok, I just tried what was basically your code, on a WIZnet device (with the current firmware), connecting to an Apache server:

var eth = require("WIZnet").connect();

var request = function() {
  var body = "";
  var options = {
    method: 'GET',
    host: '192.168.1.50',
    port: 80,
    path: "/ok.txt",
    headers: {
      "Content-Type": "application/json",
      "Content-Length": body.length
    }
  };
  var contents = "";
  var req = require('http').request(options, function(res) {
    console.log(res);
    res.on('data', function(data) {    
      console.log('DATA>'+data);
      contents += data;
    });
    res.on('close', function() {
      console.log('CLOSE');
      if(res.statusCode === "200" || res.statusCode === "204") {
        console.log('OK');
      } else {
        console.log('FAIL');
      }
      contents = "";
    });
  });
  req.on('error', function(e) {
    console.log('Error');
  });
  req.write(body);
  req.end();
};

request();

Result is:

{
  "headers": {
    "Date": "Fri, 20 Mar 2015 10:46:45 GMT",
    "Server": "Apache/2.2.22 (Ubuntu)",
    "Last-Modified": "Fri, 20 Mar 2015 10:23:31 GMT",
    "ETag": "\"d44028-3-511b5b54ad422\"",
    "Accept-Ranges": "bytes",
    "Content-Length": "2",
    "Vary": "Accept-Encoding",
    "Connection": "close",
    "Content-Type": "text/plain"
   },
  "httpVersion": "1.1",
  "statusCode": "200",
  "statusMessage": "OK"
 }
DATA>X
CLOSE
OK

And it works every time. Any thoughts about what could be different?

What happens when you use Espruino with Apache, rather than Express? Maybe Express is somehow doing something different?

As far as workarounds, if you control the server and we can't figure this our, why not just send a few more bytes?