Wolves won 2-0 through goals from Marshall Munetsi and Tolu Arokodare.
Moyes said, "I was hugely disappointed and probably a bit frustrated. I thought the first half should have been a 0-0 game.
"I didn't think that they had any real big chances to score. We gave away an absolute poxy goal that you can't believe.
"It, sort of, turned the game and turned my thoughts. We hadn't started as well as we would have liked, but I thought we were just growing into the game, and we gave away a goal when it didn't seem to be a goal in the game for either side at that point.
"So, it meant that we had to look at things and change things around a little bit."
Moyes also stated, "I think in the second half, I thought we played really well without getting a goal, which is the thing you'll get judged on – getting the goals.
"But look, we played much better. We made the changes. We want all the players to play at the top level. I said it was a 0-0 game in the first half and it should have been, but we still need to play a much higher level than we showed in the first half. That's for sure."