Hartley saw his promotion-chasing troops relinquish a 2-0 lead with 20 minutes remaining, with an Andy Jackson double earning Ray MacKinnon's men a share of the spoils in the closing stages of the game - but the Wasps gaffer feels his men will learn from their mistakes.
Hartley told Advertiser Sport, "I wasn't too hard on the players because they know themselves in the dressing room what went wrong and they don't need me to go in and tell them. We have to defend set pieces better. It was very much a frustrating afternoon for us. To be 2-0 up, you think you are going to win the game. Two set pieces that they got we didn't defend them well and that cost us.
"I thought overall it was a very good game of football. I am just disappointed we couldn't see the game out for the win. It's definitely two points dropped for us today, when you go two goals up with 20 minutes to go there is no denying that you expect to win the game but it's one of those things and a hard lesson that the players will learn from."
Alloa still sit clear four points clear in second place but now trail league leaders Queen of the South by six points but for the manager he is just looking to his own team and feels there is many positives from the game.
Hartley said, "We played well in the game and I thought attacking wise and going forward we were excellent. There was loads of positives to take from the game for us though because we played some outstanding football at times and I thought it was a real good game for the neutral.
"Credit to Brechin as well because they tried to play football too and they came to have a go. Some of the football was excellent from my players today and that was the pleasing thing for me."
Alloa's goal came from their strikers and the manager is hoping those goals will provide a welcome boost in confidence for his strike force.
Hartley added, "Our second goal was a great finish from Grehan and it was brilliantly setup by both Ryan McCord and Graeme Holmes - a real team goal. Grehan had to do a fitness test before this one as he was under the weather but thankfully for us he came through.
"It was good for us today that the two strikers got on the scoresheet and it was just a shame that we couldn't go on to win the game."