Merge proposal comment emails?

I am the maintainer of the lp:epics-base project which has the epics-core team as the driver configured so that merge proposal emails and comments should be directed to the team which forwards its emails to an external mailing list. I have just noticed that some of our code review discussions have been going to that list but many have not, despite there being no obvious difference in the proposals.

For example the proposal at https://code.launchpad.net/~epics-core/epics-base/ioc-shutdown2/+merge/224213 and its subsequent discussions appear in our list archives at http://www.aps.anl.gov/epics/core-talk/2014/threads.php?expd=00119&page=2 but for the proposal at https://code.launchpad.net/~epics-core/epics-base/spinlockfix/+merge/220845 only the initial proposal email is archived, at http://www.aps.anl.gov/epics/core-talk/2014/msg00095.php and all subsequent discussions were only being sent to me personally. My colleague who proposed the merge wasn't even getting emailed the comments until he made himself a reviewer (despite the fact that the emails I got had his address in the To: field).

Is my understanding of the Launchpad configuration correct, that these emails should be going out to the epics-core team (which does appear as a subscriber for each merge proposal) and hence to our list? I have checked the logs for our mail-server and there were no messages for the list on July 15th or 21st when I made comments on the second of the above proposals.

Is this a bug in Launchpad?

- Andrew