G'day Rob,

"Can this unfortunate state of affairs be rectified by means that don't involve more intelligent behaviour on my part ?"

Perhaps, in your Display Settings, uncheck "Edit your writeup directly in the display view, instead of in a separate page ?".

I think that removes the "Update" button after using the "Create" button; you need to use the "Edit" link for any subsequent changes. I'll check as I'm posting this and provide an update if I'm wrong. Actually, I've posted a confirmation of this behaviour, with a little more information, as an update.

It does seem that there's some timing issue (behind the scenes) which provides access to the "Update" function before all DB writes for the initial posting have completed. I've got no access to the code, so that's just a guess: "timing" could be a race condition, timestamp granularity, or something else.

Update (confirmation): After hitting the "Create" button, I was presented with a view of my node that looked like any other node posted by someone else. The only difference is an "Edit" link (top-right area, under "in reply to" link).