Paul Lambert admits Kieran Richardson deserved to be sent off against West Brom on Saturday, but says Christian Benteke's late misses were also key in Aston Villa's 1-0 defeat.
Richardson saw a straight red for a late challenge on Stephane Sessegson 22 minutes in at The Hawthorns, with Craig Gardner's 72nd-minute strike enough for the Baggies.
Defeat ended a five-match unbeaten run for Villa and Benteke twice fired wide in the closing stages -- misses which Lambert believes ultimately cost his side.
"I can see why the referee sent Kieran off, but he's not a malicious footballer," he said. "His second touch overhit the ball, but in the modern game if you raise your studs the referee will give a red card. His enthusiasm probably got him sent off.
"I thought we were the better team at that stage and it's a big compliment to the team because for 70 minutes you wouldn't have known we were down to 10 men.
"In the last 15 minutes Christian had two good chances. There's a way to lose in football and we did that today."
Lambert also dismissed claims of a bust-up between Gabriel Agbonlahor and ex-Villa assistant Roy Keane ahead of Keane's exit last month and denied that the former Manchester United midfielder created a bad atmosphere.
He added: "I commented at Crystal Palace and I said there was absolutely no issues whatsoever. It's absolute nonsense being written about him.
"To label it poisonous is shocking, absolutely shocking. Ask any of the squad that."
Information from the Press Association was used in this report.