I suggested "on touched" cause once it's set to 1 you don't have to set it again. "on is touching" would keep running every tick which isn't necessary. From what he explain he need it to switch set the animation speed to 1 when the button is touch which what "on touched object" will do. The animation doesn't change again until they stop touching. On is touching will keep running as long as it is true and keep setting the speed to 1 even when it already is one.
To stop the inverted event from running every tick add a secondary check to see if the animation is even running should be done. So if they are not touching and the animation frame isn't 0 do this.