At one point in the second half, the Warriors were leading by 20 points to six, but Smith felt that indiscipline cost them the game.
“For me, it was the same old story,” Smith wrote in his column on the Warriors’ official website.
“We were really dumb with the ball, we made too many mistakes and when you give away 15 penalties in the game, you don’t really deserve to win.
“So full credit to Hull KR, they could have packed up at 6-20, but they didn’t, they carried on going and we were left with egg on our face.”
“It was a bit strange lining up against Darrell Goulding and Greg Burke,” Smith added.
“Daz was my centre for two years and now he’s doing really well there. He created two of their tries and had a big say in them winning the game.
“Burkey’s on loan there and he’s another one who played really well. He carried the ball brilliantly.
“It’s great that he can play there for a year, get all that game time and then come back to us a better and more experienced player.
“I’m sure Shaun Wane will look at that game and what he’s done against us there.”