Olsson's clearance fell to Michael Kightly before he crossed for fellow substitute Dean Whitehead to score.
"To be honest it was the kind of game we thought it might be. The two teams cancelled each other out," said Clarke.
"It was a game of few chances. We spoke before and said it was probably a game of one chance. We said the same at half-time and unfortunately for us the chance fell to Stoke.
"Jonas made the decision to take the ball out to the touchline. For me, it's a defender's decision. He is on the pitch, he has to make that call, he made the right call.
"He made a good challenge on Jones. Unfortunately when the ball went down the line it went to Kightly. How critical do you want to be of players? That's not correct. It was not a mistake."
Clarke made six changes from the side that was beaten 3-1 at Swansea in midweek but he insisted that did not prove crucial in the defeat at The Hawthorns.
"If anyone said that's why we lost the game, they would be wrong," added the Scotsman.
"The changes were made at the end of difficult week with two long away trips to the north east and south Wales.
"The boys who played in the two away games put in a lot of effort and I thought it was right time to freshen team up."