While St Helens will rightly be deemed a champion team of some repute having added a Challenge Cup to back-to-back Super League titles on Saturday, their heartbroken opponents are once more left as nearly men.
Powell has brought Castleford so far since taking them to Wembley initially in 2014 and also a Grand Final three years later.
But, just as he did when losing a Challenge Cup final with Leeds Rhinos in 2003, he has never managed to finish the job.
There will, then, inevitably be question marks about his own ability as a coach but it would be remiss to read too much into his record just yet.
In 2003, Leeds were still waiting for their ‘Golden Generation’ to blossom. In contrast, Rhinos were in the midst of that glorious era when they defeated his still embryonic Castleford side in 2014.
The Grand Final loss against Leeds remains painful but there was mitigation there, too, and Powell has taken the unfashionable, less resourced Castleford to one of the finest eras of their history.
It will perhaps be wise to wait until the 55-year-old has taken over at a more prominent club – as he will with Warrington Wolves next season – before deciding whether or not an inability to “convert” will be a lasting image.
For now, the enduring image is one of energy-sapped players sinking to their haunches after giving everything and just coming short once more.
Castleford, looking to win the Cup for the first time since 1986, had been 12-6 ahead at half-time courtesy of a brilliant try from Niall Evalds and Jake Trueman.
Full-back Evalds was supreme, causing Saints all sorts of problems whenever he took possession, and was a worthy winner of the Lance Todd Trophy.
It was the first time a player on the losing side of a Challenge Cup final was awarded man-of-the-match since Rhinos’ Kevin Sinfield claimed it following defeat to Hull FC at Cardiff in 2005.
However, it demonstrated how dangerous Castleford had been at times and they will certainly look back and rue not making the most of their interval advantage.
The enthralling contest, played out in blistering conditions at a sun-drenched Wembley, was far closer than the final scoreline suggests.
Saints, wonderfully led by James Roby and Lachlan Coote and aided by some quality incisions from the youngster Jack Welsby, were awarded a dubious try from Kyle Amor late on which added some gloss.
Roby had also scored a highly contentious try in the 42nd minute to give his side a crucial lift but a magnanimous Powell refused to look for excuses.
He insisted: “I am super proud of the players. They have put everything into that and it just didn’t quite happen.
“Saints deserved to win. We weren’t good enough in the second half. I have no complaints.
“They put more pressure on us with their kicking game than we were able to with them.
“I don’t think we finished our sets well. We made too many errors in the second half. That was the be all and end all.
“You couldn’t fault the boys for effort and commitment but you probably could for composure.
“They put you under intense pressure do St Helens and we couldn’t really get enough pressure on their line or convert in that second half.
“Some of that was due to our lack of execution – and some due to them being the best scramble defence in the competition.”
Debate continued long after the final whistle about Roby’s try.
Coote hoisted a kick, Saints centre Mark Percival challenged and appeared to nudge forward.
The ball bounced marginally inside the touchline and Regan Grace, initially standing in touch, jumped up and palmed it back infield where the veteran hooker claimed and raced over.
Referee Liam Moore awarded ‘try’ on the field but it was only confirmed by video referee Chris Kendall after countless replays.
You wonder if it would ever have been awarded if the on-field official had not needed to make his own judgement first, a ruling which continues to seem futile.
However, Powell was indifferent to the whole affair and, rather, pointed to how his side should have claimed the initial kick and also chased harder infield.
He had a point. Saints, who had opened the scoring with Theo Fages’ 10th-minute try, pushed on with Coote adding a couple of penalties after Makinson’s try which was also deemed “soft” by Powell, his side allowing Welsby to cross the field untouched to create space for the winger.
Grand Final hero Welsby had played out of position in the halves after replacing the injured Fages at the interval but excelled.
Defeat was especially hard on veteran Castleford captain Michael Shenton and Australian prop Grant Millington who know this was likely to be their last chance of a Wembley success.
Powell revealed prop Suaia Matagi did not play, having fallen ill on Thursday, meaning Alex Foster came into his 17.
But it is hard to imagine he could have helped alter this result as elated Saints finally ended their 13-year wait for success in the prestigious competition.
Former Wakefield Trinity prop Amor said: “I really did believe that in order for us to cement ourselves as one of the great teams throughout the Super League era then we had to win today.
“We’ve gone back-to-back with Grand Finals and you can even go back to 2018 in the way we finished the league, we’ve created almost a little dynasty for our club.
“It was so important today that we got over the line. And I’m made up.”