Ewan's hard luck at the Tour de France this year continued on stage five as the Aussie was brought down by a mispositioned hay bale with less than 30 kilometres left to ride on the day.
Ewan attacked the cobble-heavy course with precision and managed to keep up with the peloton for most of the stage, before ultimately falling victim to the loose hay bale which also claimed GC contenders Primož Roglič (Jumbo-Visma) and fellow Aussie Jack Haig (Bahrain Victorious), who crashed out of the race altogether.
Ewan slipped to tenth in the points classification as a result, on a Tour already marred by two previous incidents which saw the 27-year-old lose prime position on the final sprint in stage two and have a sprint blocked by race leader Wout van Aert (Jumbo-Visma) and Peter Sagan (TotalEnergies) the following day.
"I felt good and I've actually never ridden on the Roubaix cobbles before so this was the first time, but I knew that if I could ride in a good position then maybe I had a chance," Ewan said.
"I was there where I needed to be, I felt really good on the cobbles but there was a hay bale in the middle of the road, so (it was) a bit of a nightmare.
"I don't know what happened (or) why it was on the road, but I came out of the roundabout and the few riders in front of me swerved and it just clipped my back wheel and then I just high-sided after that.
"It was on a part of the road that was not super dangerous, so (it was) unlucky - but part of it."
Ewan also congratulated compatriot Simon Clarke (Israel Premier Tech) on his thrilling stage win, and lamented Haig's Tour-ending crash in a post-race interview.
"I didn't know Simon won, but it's great for him," he added.
"(But) if Haigy is out, it's super unlucky. I think he's had some bad luck so far this Tour with the TT (time trial) and also I think he lost time on one of the stages in Denmark, but it's unfortunate for him because I think he also looked quite good - but it's a great ride by Simon."