Midway through the routine, Croft jumped into her partner’s arms, and was spun around on the floor.
However, a misplaced arm movement meant that Croft ending up spinning awkwardly with her legs in the air, before eventually recovering.
The error didn’t escape the notice of viewers at home, who shared their observations on social media, or the judges, who cited the slip-up in their evaluations of the dance.
Strictly judge Craig Revel Horwood told Croft and Radebe: “Your leg placement on the floor spin on that bum spin… something went awry there, darling, so you were in the wrong position for that.”
Shirley Ballas, meanwhile, said: “‘You are what the show is about: you started off as a beginner, and you’ve come out here and you’ve danced this. Unfortunately… the bum spin went wrong because you got the wrong arm movement.
“But, do you know what was amazing? How you recuperate. It’s not always if you make a mistake, it’s how you recuperate and you did that marvelously well, I’m very proud of you and you should be very proud of yourself.”
Speaking to series presenter Claudia Winkleman after the dance, Croft admitted she “might have a sleepless night over that one”.
“I certainly went for it. I didn’t quite expect to do a skid on the floor and end up on my back, which wasn’t quite the move I was intending,” she admitted.
“But it was so much fun, it was hilarious.”
Elsewhere in Saturday’s semi-final episode, pro dancer Vito Coppola heaped praise on celebrity partner Ellie Leach.
The couple wrapped up the episode with a Couple’s Choice dance, set to a medley of Dua Lipa tracks.
“Honestly I am so proud of this girl, I met a super shy girl and look at her now,” Vito said after their dance.
“She is super strong, independent. Before she was like ‘I cannot do that’. Everything was a no and now everything has become a yes,” he continued, before planting a kiss on Leach’s forehead.
Strictly Come Dancing airs Saturday and Sunday on BBC1.