I think what you need to ensure is a "push"  operation with retransmits.
Obvioulsy the "pull"ing of Dave to bugzilla hasnt worked
(otherwise this discussion wouldnt be happening).

Bug trackers have never worked for me either - in my current day
job i am now passed notifications of every bugzuilla opened. I
actually asked for this because i hate checking bugzilla.
Over time heres what happened:
month 0-3: Read the whole thing and called the owner.
month 4-5: Spent about a 30 second glance and may email somebody
month 6-9: Spend about 30 secs and archive them in a separate maibox
month 9-12: fuck this shit. procmail the whole thing. That what procmail
is for! Maybe someday over a fine cup of Tim Hortons French Vanilla
cappucino and donut i'll go over that list and read them all- if only we
had krispy creme donuts to go with Tim hortons coffee then i am sure i
will read them ;-> The truth is i drink Tim Hortons capucino but still
dont read the damn bugzilla mailbox. But i have it just in case i need
it ...
I can almost swear this is what will happen when you start ccing Dave
on bugzillas.

If you think of Dave as a server then the most reliable protocol
is to retransmit. Under resource constraint he dumps packets
(that del key). Add another server - Alexey - and broadcast to both
via netdev and you start to scale.
I dont think retransmission by a robot would work well either since
it misses that human touch. So you have a challenging task.

cheers,
jamal