Published: 00:00, 10 February 2019
| Updated: 11:05, 10 February 2019
Andy Hessenthaler said it was criminal Dover did not get something from their 3-2 home defeat to Harrogate at Crabble on Saturday.
George Thomson's spectacular injury-time strike snatched the points for the visitors after Whites had come from behind to lead with eight minutes remaining.
Two goals in the space of 90 seconds from Jamie Allen and Jai Reason looked to have turned the game on its head only for Harrogate striker Mark Beck's second header of the afternoon in the 84th minute to pave the way for Thomson's last-gasp winner.
It was the second time in as many weeks that Whites had lost at home to a stoppage time goal, and boss Hessenthaler admits he was fuming after the whistle. The result dropped Dover back into the National League's bottom four.
He said: "I've gone mad, I'm frustrated more than anything because I'm desperate to win. There were some really good performances out there, but with the players we've got on the pitch we've got to do better.
"It's game management, it's two weeks in a row we've not been able to see a game out and that's why I've gone mad.
"There's a lot of frustration, as a manager, sitting on that line as you can imagine when that goal goes in.
"Is is avoidable? Yes it is. It's not really good play from them it's just us not doing our jobs. It's really disappointing."
Hessenthaler said the momentum was with Dover after they'd gone in front but he felt they were guilty of switching off for the Harrogate equaliser.
He added: "You get the goal to go 2-1 up on 82 minutes, and you should go on to win the game.
"Their keeper (James Belshaw) was man-of-the-match for me, he was excellent, but again it isn't for the lack of effort, it's game management.
"I've looked at the goals and they're poor, we've got more bodies (than Harrogate) for the second and third goal, and the first goal, that was a poor goal to get off to a bad start, but we've totally dominated the second half.
"We've got experienced players on the pitch. For the second one, I think (our) players thought the ball was going out of play, and their player reacted quicker.
"He thought the best, he thought that his player was going to keep it in and we switched off.
"If they look back at it on Monday they'll be disappointed. I'd love to see the stats, I don't know how many corners we had today, it's criminal that we haven't come away with something because we were the better team, over 90 minutes we were the better team.
"If you're watching the game as a football person, or any person who likes football you think how have we lost the game. We've lost the game through poor decisions and game management and we've got to stop doing that."
Hessenthaler was pleased with the performances of scorers Allen and Reason, describing both as excellent, but he did feel keeper Mitch Walker might have done better with Thomson's long-range winner.
He added:"It was a good strike but for me he's got to save it. I've said to him, he's got to save it.
"It moved a little bit but he's got a big hand on it . That might be a little bit harsh, but we're here to try and win football matches He's had nothing to do second half it's crazy really."