How to make Space shooter boss not destroyed by DestroyByContact?

Hey Guys!
I’m total newbie to C#. And now i’m trying to improve the space shooter from tutorial and make player to fight boss. But i have a problem with DestroyByContact script. Boss gets destroyed when he collides with anything other even if he has multiple HP, same like player (who seems to work fine). He should be destroyed by function from GameController when his HP is 0. Function bossTakeLive works ok but boss still gets to be destroyed.
Here’s the script:

using UnityEngine;
using System.Collections;

public class DByContact : MonoBehaviour
{
	public GameObject explosion;
	public GameObject playerExplosion;
	public int scoreValue;

	private GameController gameController;

	void Start ()
	{
		GameObject gameControllerObject = GameObject.FindWithTag ("GameController");
		if (gameControllerObject != null)
		{
			gameController = gameControllerObject.GetComponent <GameController>();
		}
		if (gameController == null)
		{
			Debug.Log ("Cannot find 'GameController' script");
		}
	}
	void OnTriggerEnter (Collider other)
	{
		if (other.CompareTag ("Boundary") || other.CompareTag ("Enemy"))
		{
			return;
		}
		if (explosion != null)
		{
			Instantiate (explosion, transform.position, transform.rotation);
		}
		if (other.tag == "Player")
		{
			gameController.TakeLive ();
		}
		if (other.tag == "Boss") 
		{
			gameController.bossTakeLive ();
		}
		if (other.tag != "Player" || other.tag != "Boss") 
		{
			Destroy (other.gameObject);
		}
		Destroy (gameObject);
		gameController.AddScore (scoreValue);	
	}
}

Also i tried to make another script only for boss collisions but i had the same issue.
It’s third day of my fight with this problem and now i can’t find any way to solve it…

Taking out the explosion code and the tag comparison code, here is what you are left with:

 void OnTriggerEnter(Collider other)
    {
        Destroy(gameObject);
        gameController.AddScore(scoreValue);
    }

See the problem? You’re destroying the gameobject no matter what the collision conditions are. You need to put the Destroy into one of the tag check conditions.