From the GatEx thread, as it's more DOO/guard related:
Your not kidding on the euro front. I was recently in Dortmund and 'happened to find myself at the main station watching the comings and goings. A local(ish) train came in, formed of a 146 electric and 6 Double deck coaches. I watched dispatch. There were no platform staff I could see. The driver has to look out of his cab window until the train has reached about 5-10kmh. Time came to go. No whistle, but the 'guard' at the back waved, the driver, waved back and the doors closed. There were some latecomers, so the driver reopened the doors, no sign of the 'guard'. He then closed the doors again. Still some latecomers trying the doors as it moved. By now the driver was in his seat. And this was not some yokel station, but the main station of Dortmund with busy platforms. H&S and lawyers would have a field day in the UK with a bad dispatch as I saw. . I left the platform shaking my head.
That sounds very much like a new-style DOO operation to me. The driver is fully responsible for dispatch, and it is primarily done with the door interlock (yes, really, that's the hole in it to me) rather than using the Mk1 eyeball. It would seem that, like on the Swiss narrow gauge lines which are near enough all DOO, if there is a ticket examiner on board the driver waits for a tip just in case the ticket examiner wasn't on board or was dealing with an issue, but that tip is not safety-related and does not indicate that the guard has said the train is clear to depart.
In most places (except for some reason Hamburg Hbf, and some S-Bahnen) DB hasn't used platform staff for years, nor do most other European countries.
FWIW you can tell a DOO dispatch from a non-DOO one, because for a guarded dispatch you get the old "An Gleis N bitte einsteigen, Tueren schliessen selbsttaetig..." autoannouncer before the whistle (also absent on DOO) goes.
The guarded DB dispatch process (you'll see this on ICE/IC plus any remaining older regional stock) is much more like the UK one:-
1. Guard operates key in platform box, "An Gleis N..." announcement sounds.
2. Guard blows whistle.
3. Guard checks doors are clear and operates key to close doors except local door. (It is notable that like on Voyagers doors on DB are released, if not done automatically on dropping below 5km/h as on very old stock, by the driver)
4. Guard confirms doors are closed, and either (depending on station) operates key in platform box to give RA, shows the RA bat to the driver, or if very close says clearly "Abfahren, bitte".
5. Driver departs. Guard remains at open local door and watches train out of platform.
6. Guard closes local door and proceeds with other duties.
Notably on DB a guard never dispatches from the cab, only ever from a passenger door.
Also worth adding that under the new DOO the doors close of their own accord like lift doors and will not close if obstructed (both using a beam and edge detection, I think). If they are, the driver has to leave the cab, walk back and operate a switch on the door to override the check. Wouldn't work in the UK - people would deliberately block them. The driver can only lock them from the cab, not initiate a forced closure. This is similar to how rear doors work on German buses.