AfterFX.com always returns 0

I have an application that invokes the afterfx.com executable with a script using the -s flag, the script sets app.exitCode and then calls app.quit on an error. The problem is the return code is always zero no matter what the exitCode is set to, how am I suppose to detect the state from the controlling application without exit codes?

The script contains only:

app.exitCode = 2;
app.quit();

Platform is Windows 10 Build 10240 64bit, AE 13.5.0.347