The Blades are now within six points of safety with three games remaining.
Asked if his side now had realistic chances of avoiding the drop, Adams said: "We don't know. We just keep going.
"We asked them to show a bit of pride and passion in their own performance and be brave and that's all they can do."
But he said: "The crowd are entitled to their opinions aren't they? If Williamson had played the whole 90 minutes he wouldn't have played at Reading on Saturday.
"His body can't recover as quickly as other players because of his back, so the crowd can do and say what they want, I've got big broad shoulders."
City manager Keith Millen admitted "too much had gone on in the game" for him to be happy with their performance.
He said: "Where do you start with that? It could have gone either way, whichever team took their chance (would win) and they took theirs with a good finish."
Millen felt Nicky Maynard had been harshly treated by referee D'Urso after watching the replays of his first half sending-off.
Millen added: "At the time I felt he could send him because he slid in, but he got a slight touch of the ball.
"The wet pitch didn't help, he slid through the lad and just caught him, so we'll assess it on the way home."