Nardiello was booked following a clash of heads seconds before the end and when he continued his protests after the final whistle, he was shown a second yellow card by referee Dean Whitestone.
Jon Taylor gave the visitors the lead with a headed goal after 20 minutes, and it took Rotherham until the 56th minute to equalise through Alex Revell.
Shrewsbury again took the lead after 62 minutes when Tom Bradshaw tapped in from close range but Nardiello came on after 65 minutes and soon headed the home side level from Ben Pringle's free kick.
"He came on having not played a minute for three weeks and got us a goal," said Evans.
"I thought Shrewsbury had a man extra all over the park today .We didn't start properly and we weren't focussed, but in the second half, after we had them in at half time, we settled down and got back in the game.
"Shrewsbury's second goal was offside for me. The ball goes through a ruck of bodies and our keeper made a great reaction save and the boy was on his own when he tapped in and he can only be offside.
"In the past we would probably have buckled at that, but it was a great ball into the box and a great header by Nardiello."
Shrewsbury boss Graham Turner said his initial reaction was one of disappointment, but Evans countered: "Based on chances, we should have won the game because I don't think they had a chance in the second half and if Graham says he is disappointed then when he looks at the DVD he'll think he was lucky."