Chrome Dino slows down but doesn't die

dino4kids.js

//Paste this code into console (CTRL+Shift+I / F12)

function customGameOver(){
    let timer;
    return ()=>{
        clearTimeout(timer);
        timer = setTimeout(()=>{
            this.playSound(this.soundFx.HIT);
            let csp = this.currentSpeed;
            if (csp/2 < 4){
                this.setSpeed(4);
            }else{
                this.setSpeed(csp/2);
            }
        },25);
    }
}
Runner.prototype.gameOver = customGameOver.apply(Runner.instance_);
//to restart
// Runner.prototype.restart.apply(Runner.instance_);