Duvida com Thread com sua sequencia de execução?

public class ThreadExcept implements Runnable{

	   public void run() { 
	System.out.println("passo 3");	   
		   throw new RuntimeException("exception "); 
	   }
	  
	    public static void main(String [] args) {
	    	System.out.println("passo 1");	
	      new Thread(new ThreadExcept()).start();
	      System.out.println("passo 2");
	      try {
	    	  System.out.println("passo 4");  
	        int x = Integer.parseInt(args[0]);
	        Thread.sleep(x);
	        System.out.println("passo 5");
	        System.out.print("main ="+x);
		   
	        
	     } catch (Exception e) {
	    	 System.out.println("passo 6");
	    	 System.out.println("Exception Erro="+e);
	     }
	   }


}
---resultado :

passo 1
passo 2
passo 4
passo 3
passo 5
main =1Exception in thread "Thread-0" java.lang.RuntimeException: exception 
	at br.com.ThreadExcept.run(ThreadExcept.java:7)
	at java.lang.Thread.run(Unknown Source)