Sam Wood scored the only goal of the game after 32 minutes after coming off his wing to fire a low shot into the bottom corner of the net.
With the clash one of only three League Two games to go ahead, Burnett admitted that his play-off chasing side had missed a trick.
"We are obviously disappointed, we are just ticking along under the play-off places and if we had won here that would be 40 points and just off the play-offs," said Burnett.
"We had a real chance to put some pressure on the teams above us but this game wasn't a Dagenham performance and that is disappointing.
"It is one step forward and two steps back. Losing Dwight Gayle and Michael Spillane wasn't why we lost this game, we as a group didn't perform. We were second best from one to 11 and we have to move forward.
"But we have got some good young players under the surface. Louis Dennis came off the bench and has come back from Canvey Island and has the potential to be a top player, he just has to show it on the pitch now for Dagenham."