With the territory stats leaning heavily toward Counties, the tackle count and breakdown stats painted a vivid picture of the one-sided affair.
After 67 minutes, Northland had made 118 tackles compared with 39 by Counties, while Northland had 33 breakdowns compared with Counties' 110.
"Individual errors were costly at crucial times," Harris said.
"It's a product of play loosening up and where we lose the game is when it's highly intense and everything's riding on it. Certainly there's an attitude to try and get that [intensity] but it's just the execution of those things - when we tried to get things going we made mistakes."
Although the side survived the loss free of major injuries, the possible omission of Dan Pryor for Friday's clash with Bay of Plenty is of concern after he failed a concussion test around halftime.
"He'll get tested through the week but could well be out for this week given the short turnaround," Harris said.
"To be honest, it was one of those games that, apart from Dan Pryor, we got through pretty clean - the only other big blow was losing Dave Thomas in the captain's run the day before," Harris said.
"We don't really know if he'll be right for this coming game but having said that we're hopeful that we will be getting Shane Neville back."