Dean Saunders absolved his goalkeeper of blame, after a late Oldham winner slipped through his hands.
The Chesterfield boss watched his men take a 1-0 lead into half-time, but the Latics came back in the second half with two goals.
Spireites stopper Tommy Lee first parried a shot into the path of Dominic Poleon, who swept home the equaliser, and then failed to hold Danny Philliskirk’s 87th minute effort, the ball hitting the post, Lee’s back and finding the net.
But Saunders refused to criticise the goalkeeper, highlighting instead the role the conditions played with heavy rain throughout the match.
“We didn’t play our normal style of football, our normal passing game,” he said.
“But the conditions were horrific, it was bordering on nearly being called off at one stage. It was difficult for both teams.
“The goalkeeping mistake at the end from Tommy - he’s got us so many points this season so I’m not going to criticise him - it was just a routine save, straight at him and I think it squirms through his legs, because of the weather. The game slipped through our fingers.”
He admitted the Chesterfield performance wasn’t of the standard he’d expect, and reiterated that the rain and slippy surface played a big part in the defeat.
“Our crossing, our passing, the link play, we didn’t show enough quality,” said Saunders.
“We didn’t make their goalkeeper work enough.
“‘ll put it down to the conditions, they never created much, they had two shots I think and scored.
“Today the rain and the water on the pitch spoiled the game.
“We could have run out 1-0 winners, but things seem to be contriving against us at home.”