Andrew Crofts grabbed two second-half goals, either side of Ched Evans' strike for the Blades, as the Canaries bounced back from a below-par first-half showing to claim three points and leave Adams still waiting for his first win as United boss.
"With the first one, leading up to the corner, there's quite clearly a trip on Kyle Bartley which the referee missed," he explained.
"It goes out for a corner and the ball then comes in to the box and there is a foul on (goalkeeper Steve) Simonsen in our view.
"Then the second goal, Ched Evans clears the ball and their fella jumps into him. It's a foul, but he (referee Andy Haines) has missed it again.
"When you are down at the bottom it goes against you, but you hope over the course of a season it evens itself out."