When developing client side javascript applications, the developer network panel is invaluable for debugging network issues:
I know it's not pretty, but you could always output the content of the response headers on the console inside your request call:
var req = https.request(options, function(res) {
console.log("statusCode: ", res.statusCode);
console.log("headers: ", res.headers);
res.on('data', function(d) {
process.stdout.write(d);
});
});
Your original question, however, was not about problems with the server side but rather a problem with the node code itself so this wouldn't be of much use here.