Here's some more background on this, as part of my job I have to do code reviews of Open Source components that my group supplies for internal use at my place of work. With Hibernate we found a few potential issues, most of which we able to determine were non-issues, the only one outstanding is the one I reported above.
Following the procedure at
http://www.hibernate.org/217.html about opening JIRA's it stated that one should first ask here on the hibernate-users forum.
I'd be interested in getting feedback from the hibernate devs about this, and if the code changes I'm suggesting are warranted or not. If I don't get any feedback in the next couple of days I'll open a JIRA on this.
Many thanks
Mick