Chris Wood had Forest ahead before Jean-Ricner Bellegarde quickly equalised.
O'Neil said, "Improvement and it's a tough place to come.
"A fairly even game and a fair result. Lots of good bits and crazy bits, but a good solid away performance where we looked a threat and we weathered pressure. It looked like we could have scored a winner.
"It was a poor goal from us to concede, but we were able to bounce back. Off the back of a busy week and a tough week - the 6-2 defeat to Chelsea, cup game and transfer window.
"It's an unsettling week for everybody there's a lot going on."
On Sam Johnstone's debut and Jose Sa remaining at the club, he said: "A good debut and he has not played much recently, it was a good start to his Wolves career.
"It's an unsettling week, there is a lot going on, Jose Sa had a bit going on.
"I had a big decision around goalkeeping and we decided it was Sam today. But Jose will be back training with the group when he returns from Portugal. The idea is him and Sam fight it out for the shirt."