Wycombe boss Gareth Ainsworth was dismayed by the decision to send off Anthony Stewart in his side's 2-0 defeat at Dagenham.
The Daggers doubled their lead from the penalty spot just two minutes into the second half when Stewart hauled down Rhys Murphy as he advanced towards goal and was promptly shown a red card. Murphy coolly slotted home the spot-kick.
Afolabi Obafemi had put the hosts ahead in the first half.
Ainsworth, whose side are now without a win in six games, said: "He's got the ball - anyone could see that. But the referee sees it otherwise and we're then forced to chase the game.
"You could say the game was already over after they'd scored the penalty.
"It's been another disappointing and frustrating day to be honest.
"I knew we were going to be in for a really tough test, but we've also not really helped ourselves with some of the defending I've seen out there.
"If we have got designs on moving up the table and making good progress this season, we've got to get better.
"Sometimes it's as though we try a bit too hard - just that extra bit of composure here and there can make that difference.
"We'll keep plugging away and we'll soon be back on the right track again.
"I think the fans have seen enough good things from their team since the beginning of the season."