Mick McCarthy's side threw away a 1-0 lead as Spurs scored three late goals to take all three points at White Hart Lane.
American keeper Hahnemann, who was jeered by Spurs fans who thought he was slow to take goal-kicks when his team were ahead, was unhappy he was booked for complaining about time-wasting during Roman Pavlyuchenko's celebration after Spurs' second goal.
"The referee was on me the whole time," fumed Hahnemann.
"The ball goes out for a goal-kick, I run, get the ball, put it down and he's on at me to play quicker. What am I supposed to do? It's an absolute joke.
"Then they go and celebrate for 30 minutes in the corner and I say, 'How about them time-wasting now?'. And he booked me. It's just typical."