Sloppy defended contributed to the opening goal, as the home side outbattled the Iron for the opening 20 minutes, and Laws was surprised at how confident Rushden were considering their lowly League position.
He said: "It was a disappointing display in the first-half, in particular the first 20 minutes.
"I thought we were too open. We had opportunities to clear the ball for their goal, it was certainly amateurish and we didn't clear our lines.
"Credit to Rushden, they came at us and we couldn't handle it. They were unlucky not to be 2-1 to be up at the break with their shot that hit the post.
"We tightened things up at the break, and looked the better team."
Centre-back Butler did his burgeoning reputation no harm with his double strike, both form Peter Beagrie corners, and Laws singled him out for praise.
He added: "Andy was awesome, he won everything. He won every header and took his two goals very well."
Diamonds boss Ernie Tippett was keen to draw on the positives for his side.
He said: "We have to take heart from the first-half performance, which was excellent.
"I was disappointed with the two goals that came from the corners, and ultimately the second goal for Scunthorpe was the turning point.
"Their third goal was a good goal, but we don't want their players shooting from distance, and we should have defended much better."