After losing for the first time this season last week against Chesterfield, Ryan Williams, Deane Smalley and Asa Hall grabbed goals to get the U's back on track.
Pools, who had Steve Howard sent off in stoppage time, had levelled through Luke James' 47th-minute goal.
"I think we all have to admit- and I reiterate we have had nice things said about us again - we didn't perform in the first half," Cooper said.
"We are trying to force ourselves on the game and to concede after five minutes and go behind, it's not great for us.
"Then we get a foothold in the game again, get to half-time and felt as though we were back in it.
"To start the second half as we did was as pleasing as the first-half start was disappointing.
"If you analyse their second goal, it shouldn't be allowed to happen. We are disappointed with that.
"Then we go chasing the game, tried to force the hand and in the last five minutes, it's not good, it doesn't look good as we concede a penalty, and have a man sent off.
"But there wasn't much in the game. It was maybe not enough to win, but we levelled and had a good chance for an equaliser saved to make it 2-2 - and I would have took that."