The Black and Whites were embarrassed 46-6 there in March, a disconsolate Radford admitting afterwards it was the most difficult loss to stomach of his reign.
It was when he then disclosed his squad had barred him and the rest of the coaching staff from the changing rooms, though, that the story escalated.
Essentially, as was discovered later, it was not a challenging of his command in any way, but merely the under-performing players wishing to quickly get to the heart of the matter of what was a pathetic display.
It had been a third successive loss although, admittedly, the campaign was only five rounds old.
Indeed, as it now stands, they head back there tonight top of Super League, in the Ladbrokes Challenge Cup final and hoping to achieve a clean sweep of domestic trophies.
One of the bedrocks of their scintillating form since – Hull won 15 of their next 16 games – has been marauding centre Mahe Fonua who returns this evening after a concussion.
Asked about his memories of that last trip to Widnes, he recalled to The Yorkshire Post: “I didn’t play and I’d already set off for the hospital with Fetuli (Talanoa) as he got concussed in that game himself.
“I only found out afterwards what had happened but whatever anyone thinks about it it was a bit of a turning point for our season anyway. We did go on and win a couple of games after that so I’m not sure Radders is holding any grudges…”
That may be so but Radford certainly wants a response from his players now after the disappointment of Friday’s 30-16 defeat to visiting Castleford Tigers in the Super 8s opener.
The East Yorkshire club looked strangely out-of-sorts then, but it was perhaps unsurprising given the enormity of the previous week’s Challenge Cup semi-final win over Wigan Warriors and the fact they were missing Fonua, winger Talanoa and prop Liam Watts, who all now return as Hull step up their bid for the League Leader’s Shield.
Fonua, who has scored eight tries in 20 games since joining from Melbourne Storm last winter, missed the Castleford game after being stretchered off against Wigan with a sickening head knock.
“As bad as it seemed I probably just don’t remember that bit – the incident itself – but everything leading into it and afterwards I do so I’m grateful for that,” he said.
“There was no major injury that came from it and I’ve now passed all the tests I needed to.
“I’m pretty keen for Thursday as I had last weekend off and the boys didn’t go too well so I want to do all I can to help get us a win.
“Missing last week could be a blessing in disguise; it’s a long season here and I’ve freshened up again.”
That statement could strike yet more fear into opponents who have generally been bullied by the hulking Fonua already this term.
Now he feels invigorated further for the final push.
At 16 stone and six foot one, he is a formidable presence, and so, with his robust Tonga team-mate Sika Manu alongside him at second-row, Hull’s right edge is as dynamic and powerful as they come in the competition.
Fonua, still only 23, said: “Sika has been a strong workhorse for us; he lays the platform, sets the standard and we just try and help out.
“I am really grateful for how this first season has gone.
“We finished league leaders at the end of the regular season and we won that semi-final to get into the Challenge Cup final.
“I know now that that is a real big thing here. Just over the last couple of weeks I’ve come to learn how excited this city is about it; just walking around and people coming to say ‘g’day, congratulations for bringing this town the chance to go to Wembley!’
“If someone had told me last year we’d be in this position I’d have penned the paper (contract) straight away.
“But things have panned out really well for us and I’m glad to be a part of it.”
He started the campaign on the wing and was given jersey No2, which surprised the Melbourne-born player as he always thought he had been recruited as a centre.
However, the switch to his preferred position was soon made and it reaped further dividends.
Meanwhile, seventh-placed Widnes lost at Catalans Dragons last week and, realistically, have no chance of now reaching the top-four.
But Fonua insisted: “They are always tough at home and have beaten some good teams there this season. It happened at the start of the year where they put those big points on us so we are going down there with a bit of redemption in mind, too.”