Using /t 0 implies the /f (force) switch for shutdown, that may probably be why it doesn't send the pre-shutdown event to all active applications?
That didn't sound right to me, so I did a shutdown /? and found this.
/t xxx Set the time-out period before shutdown to xxx seconds.
The valid range is 0-315360000 (10 years), with a default of 30
If the timeout period is greater
than 0, the /f parameter is