Well done to all involved, just a shame the outcome wasn't the best this time round.
Having been on the delivering end of several Comp "A/B" flights, I know I ALWAYS looked on it as a;
"Do what I can today, for tomorrow it might be me needing the help!"
situation.
In my experience, ATC have always been extrememly accomodating if/when they are aware of the nature of these flights, and for that I thank them all.
I can only remember 1 occasion where someone got annoyed because of a comp A.
We had just go all 4 running when we were informed a Puma was inbound with a comp A on board. The Puma was 60 minutes out so we shut down and waited. After explaining to the pax what was going on, everyone (except an army colonel) settled down for the duration. The col. in question started threatening all sorts to try to make us depart on schedule, even threatening to call 2 and 3 stars in London. The captain was an old hand, and his reply is one I'll never forget.
"You can call God for all I care, because we aren't going anywhere until that guy is on-board. If you want to be aboard when we do leave, then I suggest you sit down and shut the **** up, Sir."
The col. never did make that phone call!
Long may the system remain untouched and effective, and long may everyone involved keep up the good work.