Why is CRLF treated differently when called via bridgetalk?

I bumped into yet another mystery: When I run a script directly in ExtendScript, it interpretes the '\r' as a CRLF. Yet, when I called it via bridgetalk, the '\r' was left as text.

This strange behavior exists if I set target to photoshop or not. Can someone tell me why please?

Below is the unit test (CS6, Windows 10)

- Calling script:

#target bridge

var bt = new BridgeTalk; 
bt.target = 'photoshop'; 
var myPath = '~/Desktop/testCarriageReturnSubstitution.jsx';
var scriptFile = new File(myPath);
var fOpen = scriptFile.open('r');
var script = scriptFile.read();
$.writeln(script);
bt.body =script;

bt.send();

- Test script:

#target photoshop

var badString = '\rTitle\rCity, State - USA   December 2015';

var newString = badString.replace('\n', "\n");

$.writeln (badString);

$.writeln(newString);

Result when running directly via ExtendScript:

Title

City, State - USA   December 2015

Result: undefined

Result when invoked via calling script:

Result: true

\rTitle\rCity, State - USA   December 2015

Thanks,

/Tim