"We had three sitters in the first half when Kamara, Campbell and Kozak were guilty of three bad misses," said the Baggies boss after the 1-1 draw.
"I also thought the referee helped Birmingham when he awarded them the penalty, as he should have given us a free-kick for a foul on Kevin Campbell.
"It created a difficult situation for us so I have to give my players credit for the way they battled back.
"This match gives us something to build on as our previous three performances have been very good, but the results have gone against us.
"But that is our fault as we are not taking our chances and if you do this you will always struggle.
"We could have won late in the game but Nathan Ellington was unlucky when his shot hit the bar and came out.
"Ellington's goal will do him the power of good. He could have had three goals and that is the spark he needs as he is a confidence player.
"I have no doubts the relegation battle will go down to the wire on the basis of recent results."