New striker Lewis Flatman – in his second game for the club – gave the visitors the lead on five minutes with a fine shot into the bottom left-hand corner from just outside the box.
Jack Selby equalised for Camberley on 60 minutes with a shot into the corner, but Flatman scored his second of the night on 66 minutes when he cut in from the left and curled a superb shot into the far corner.
Both sides had chances to win. Flatman almost completed his hat-trick but was denied by an excellent save by the Camberley keeper, while the hosts nearly scored when a free kick was whipped into the six-yard box but missed everyone before bouncing wide.
“We were in control twice, but then again could have quite easily lost it at the end,” said Johnson. “I said to the boys that defending crosses is becoming embarrassing. It’s becoming a habit.
“It’s so frustrating – it’s been there since we’ve come in. We work on it and we try to make them better. I think they’ve improved as defenders from outside the box, but inside the box it’s miles off.
“I’m picking the players but they’ve got to take responsibility. They’ve let the midfield down and they’ve let the strikers down, because they worked their socks off tonight.”
Despite his frustration, Johnson praised Flatman for his performance, as well as picking out a number of other positives on the night.
“I thought Lewis looked a cut above everyone,” said Johnson. “He had good touches, and nice quality on the ball. He’s a positive – there’s loads of positives. Just unfortunately defending crosses is an issue.
“Richie Mbele and Lamar Koroma were excellent in midfield, battling away – I think they had the better of their three in there.
“It was a little bit disjointed as right-back Max Meaton had to play left-back as we had no left-footers, which made us a little bit unbalanced. Owen Dean was a threat, and Connor Young come to life late in the first half and found pockets, so there’s plenty to be positive about.”
Tuesday’s draw followed a 3-0 defeat for Farnham on Saturday at home to league leaders Raynes Park Vale.
Johnson praised Vale for their performance.
“You can see why they’re up there,” he said. “They’re a well-drilled side and were the better team in both boxes. We want to be up there next season and take their place, but our defending needs to be better from set pieces.”
Next up for Farnham is a trip to lowly Banstead Athletic on Saturday (3pm), and Johnson wants to see an improvement defensively.