Bug in Source Code but Can't Find It

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Puck : MonoBehaviour
{

    public delegate void GoalHandler();
    public event GoalHandler OnGoal;

    public float deceleration;
    public float startingHorizontalPosition;

    private Rigidbody puckRigidbody;

    // Start is called before the first frame update
    void Start()
    {
        puckRigidbody = gameObject.GetComponent<Rigidbody> ();
        ResetPosition (true);
    }

    // Update is called once per frame
    void FixedUpdate()
    {
        puckRigidbody.velocity = new Vector3 (
            puckRigidbody.velocity.x * deceleration,
            puckRigidbody.velocity.y * deceleration,
            puckRigidbody.velocity.z * deceleration
            );
    }

    void OnCollisionEnter (Collision collision) {
        if(collision.gameObject.tag == "Goal") {
            if (OnGoal != null) {
                OnGoal();
            } else {
                gameObject.GetComponent<AudioSource>().Play();
            }
        }
    }

    public void ResetPosition (bool isLeft) {
        transform.position = new Vector3 (
            startingHorizontalPosition * (isLeft ? -1 : 1),
            transform.position.y,
            transform.position.z);
            puckRigidbody.velocity = Vector3.zero;
    }

}