The Bucks saw a 3-1 half-time lead slip away at Spennymoor Town, who overcame the dismissal of captain James Curtis to deny the Bucks all three points with a 96th-minute equaliser from right-back Tyler Forbes.
Cowan struggled to contain his feelings after the game, and admitted that his patience had run thin.
“It’s a little bit like the straw that broke the camel’s back for me, in terms of the players and conceding late goals,” he said.
“Again, we have a chance from a yard out and one of our two top strikers just needs to side-foot it into the net from a yard out, which they don’t.
“They then they go and equalise with the last kick of the game.
“It just shows a weak mentality, which is really disappointing, and it’s one I’ve taken personally.”
Cowan, accepting that fans might be fed up of hearing the same lament, felt no less wearisome at his team’s inability to see the game through.
“People might get bored of me talking about it, because you’d like to think that people would learn,” he added.
“One thing we can’t do is to stick it in the onion bag for them, and another is that we can’t defend for them.
“I spoke to a friend of mine, who’s an opposition manager, and he said ‘you need to be creating more chances’ and I laughed, because we’re creating four, five and six a game, but we just don’t convert.
“It’s not laughable, it’s too raw for that. I’ve never seen it as a player, to concede so many late goals as we have this year, and to dominate games.
“It shows the players are good enough, but unfortunately it also shows, perhaps not as individuals but as a group, that we have a soft underbelly, a weak mentality. That’s just my honest opinion and I feel I have to voice that now.”
Cowan didn’t go all out on his side, however.
“I thought the performance was good on the whole,” he inissted.
“We were the better side, against a form team. We’ve come to Spennymoor and been far and away the better side.
“They were celebrating like they’d won the World Cup. We dominated and they didn’t like it, their behaviour showed they didn’t like it, but they’ve nicked it at the end.”