The Coasters couldn't make it three National League wins in a row as Will Evans headed in the winner four minutes from time.
That was after Danny Rowe had equalised for the visitors in the second half following Shamir Fenelon's opener.
Both teams were then reduced to ten men - Jack Muldoon was sent off for the visitors in the second half for an off the ball incident before Aldershot sub Manny Oyeleke saw red for a bad tackle.
"On balance, we probably didn't deserve anything from the game," said Challinor. "Being honest, first-half we were nowhere near and we didn't play. For some reason we didn't get on the ball and express ourselves.
"I expected it to be an open game, I expected there to be goals.
"Second half was better but poor decision-making right the way through has cost us. In fairness, the run that we've been on our decision-making has been really good which has got us our wins.
"To lose it is disappointing, but you couldn't say that you didn't see it coming."
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