The midfielder fell and skied his late spot-kick as he squandered the chance to rescue a point at The Hawthorns.
The Gunners went down 2-1 and missed the chance to go top of the Barclays Premier League while title rivals Manchester City were thumped 4-1 by Liverpool.
But Flamini insisted Cazorla should not shoulder the responsibility for the loss after Arsenal dominated but failed to recover from Mikel Arteta's first-half own goal.
"The penalty, it can happen and Santi falling...there is nothing you can do," Flamini told Arsenal Player. "We tried and tried and tried until the last minute but we can't give any excuses - we lost the three points.
"It's a shame because we started the game well, we went 1-0 up and then after they scored [twice] before half-time it became more difficult for us.
"We tried to push on in the second half, we had some opportunities but of course it is disappointing because we didn't get any points. Sometimes it happens and now it is important to recover and focus on the next game."