Britain were awarded their sixth medal long after the supporters had filed out of the Luzhniki Stadium and the athletes had returned to the team hotel.
The women's 4x100 metres relay team were upgraded to bronze to help make up for the disappointment of watching the men stripped of their medal of the same colour following the now-customary baton changeover debacle.
It meant Britain departed Russia with three golds; a joint record tally for a World Championships with 1993 in Stuttgart, thanks to Mo Farah and Christine Ohuruogu and three bronzes.
The target set by UK Sport for the championships was six to eight medals. "I really feel inherently positive," said Black, who is also acting head coach. "I'm so excited and enthusiastic. But I'm a realist, it's been a tough year and this is the World Championships, we've got to remember that."
The year after London 2012 was always going to be difficult as the sport started its build-up to the next Olympics in Rio in 2016, and the World Championships in London in 2017, and athletes re-evaluated their future. Black termed it a "transition year" and, in addition, the team were hit by more than their fair share of injuries, with the likes of Jessica Ennis-Hill missing in Moscow. Black hailed the 18 top-eight finishes by British athletes as "an enormous achievement" and said the athletes who missed out would return even hungrier for success.
"It was great to see Tiffany Porter [bronze, 100m hurdles] replacing a Robbie Grabarz [Olympic high jump bronze medallist who finished eighth] and I'm sure Robbie will have learnt from this championship and will be even more determined going forward.
"[Pole vaulter] Holly Bleasdale, [sprint hurdlers] Andrew Pozzi and Lawrence Clarke [all three missed the championship] will be so determined. Jess, I know, is going to come back with a vengeance and Mo and Chrissy are showing signs of still being ongoing. So, no, I'm not concerned. It would have been great if it was more [medals]. It could be, it should be and I'm hoping it will be in the future."
Fitness issues also ruined the build-up to the event for Dai Greene, the defending 400m hurdles champion who went out in the semi-finals, while, in the women's event, Perri Shakes-Drayton suffered a knee injury in the final which led to her finishing seventh and having to fly home.
Perhaps the most exciting British performance of the championship came from another athlete who did not win a medal, but Adam Gemili's fifth place in the 200m final offered such huge promise for the future.
He ran 19.98 seconds in the semi-finals, becoming only the second Briton to break the 20sec barrier, and was praised in the medallists' press conference by Usain Bolt.
"In the last few days he demonstrated he had moved on to another league," said Black of the 19-year-old former footballer who reached the 100m semi-finals at London 2012. "We have to understand that, embrace that, support, protect and assist. He has huge potential. How far he can go we don't know at this stage, but we are incredibly optimistic."
Black's next task is to help find a permanent replacement for Peter Eriksson as head coach, the Swede who replaced Charles van Commenee after London 2012 but left the role this summer for family reasons.
On the evidence of the past fortnight the new man will have much to work on, but also much to work with.