Only a Sean Gregan goal 18 minutes from time rescued a point and Megson was far from pleased with the reaction of some of the Albion players after the game.
"That's two points lost without a doubt," Megson said after the 2-2 draw at The Hawthorns.
"The way the game started was everything we wanted, not just with scoring an early goal but because we were well in charge and were getting in dead easy.
"But then I thought one or two of our players began taking liberties and that's cost us the points.
"We took liberties at the back when certain people began thinking the result was already there for us. The defending for the corner from which they scored there first goal was an absolute crime.
"If I took them back out on that pitch and put in 50 crosses but told them I'd fine them if they let in one goal, they wouldn't let one in. But Crewe sail two balls into the box and we can't deal with it.
"There were one or two players in there who did not do what they were supposed to have done and what they had been doing earlier in the season, because if you're a defender, first and foremost you defend.
"At 1-0 the result should not even have been at risk given the way we started and if we're going to have pretensions of winning the league we have to do better than that.
"Our home form is now a cause for concern because although we're top of the league and we're at the halfway stage of the season, we're not winning at home and that's getting the players anxious and it's getting the crowd anxious."