Troubles with detecting end of animation clip using Animator in Unity2d (4.5.5)

Hello! I am developing video game and I have main character with list of animations (Walk, Idle and Fight). Walk and Idle animations are set as looped and the fight animation does not looped. I need to play the fight animation every time, when user taps the screen. I have the boolean variable to start the fight animation and when the user taps the screen I am sending message to the AnimatiorController anim.SetBool("IsFighting", true);. But my animation clip is not looped, it is in a "single mode" so, how can i reset IsFighting variable back to false to give to the user an ability to fight again? I have read this topic End of animation clip using Animator (Mecanim) and I decided to make condition for transaction from fighting animation back to idle mode with the help of the Exit Time, but I had no success. For example my fighting animation has 12 frames and 24 frames = 1 second and so I need set exit time to 0.5? I did this, but in this case fighting animation doesn't playing when the user taps the screen. Why can it be so and what I am doing wrong? Here are my conditions to animation transactions idle->fight boolean IsFighting = true; fight->idle ExitTime = 0.5
And the second question: if the user will quickly tap the screen many times in a row? How to be in these situation and play animation properly using Animator? Thank you for interest to my topic! I'll be very pleased for any help!