Newcastle looked to have snatched a barely-deserved victory 16 minutes from time when Jack Colback fired home off the inside of the post.
Carver admitted his players had lacked professionalism in failing to see the game out to secure what would have been back-to-back league victories.
He said: "It's hugely frustrating. It wasn't a classic, was it? It was a pretty average game, certainly one game that is not going into my DVD collection.
"There are two minutes on the clock, we get a free-kick, it goes into the final third, we play four or five passes backwards back to our goalkeeper, who kicks it. We are out of shape and before we know it, it's in the back of the net.
"Now that's not professionalism, for me. There are two minutes left on the clock, go and run the ball into the corner and see the game out 1-0 and take a scrappy 1-0 victory.
"But it wasn't to be. That's why I am frustrated."