To invert a condition you just need to right lick it and select invert.
Another easy way would be to give your character object an 'instance variable' or 'Boolean' called colliding.
In your collision event set the Boolean to true or the variable to 1, then use the timer object to revert it back to normal when your animation is due to finish. Then just add another condition to your 'on any touch end' event that makes sure that the Boolean is false or variable is set to 0 before it sets the animation.