The Dutchman was unhappy with how things panned out early in the piece after watching his side lose two matches in a row to relinquish top spot and admitted he gave his players a bake at half-time but was content after they showed what they are capable of as the match progressed.
"I wasn't happy with the first half. We made a couple of mistakes in the first minutes, and then we had some problems trying to come back into the game," Coolen said.
"It's not necessary, that's what we showed in the second half, that we can play football, that's what we had to do.
"There were some strong words at half time a few players were not doing their jobs. Everybody can make mistakes, that's not a problem, but there were people not doing their job and not playing football in the first half.
"To be honest I'm really happy with how they picked it up in the second half, and they played football, and we scored a few good goals and had a few good chances so I'm real happy with the second half, but definitely not with the first half," Coolen added.