Null Reference Exception for a Full Match 3 Board

When I make a match in my match 3 game (like Bejeweled or Candy Crush) it recognizes the horizontal match, destroys the pieces, drops down pieces that are above to fill its place, fills in the top row's gaps, checks for a cascade, and says that the matched pieces have not been replaced (via exception) even though I can see them getting replaced. Here's some of my code; thanks in advance for being awesome at coding!

Code (CSharp):

1. void FallIn(Vector2 dotPos)//For every dot that's above this dot, move it down.
2.     {
3.         Debug.Log(dotPos.x + ", " + dotPos.y);
4.         for (int row = (int)dotPos.y + 1; row < height; row++)
5.         {
6.             allDots[(int)dotPos.x, row].GetComponent<Dot>().row--;//When this is called all of the pieces lerp down due to their update function
7.         }      
8. //Replenish the top row
9.         int dotToUse = Random.Range(0, dots.Length);
10.         GameObject dot = Instantiate(dots[dotToUse], new Vector2((int)dotPos.x, height - 1), Quaternion.identity);
11.         allDots[(int)dotPos.x, height - 1] = dot;
12.     }

Code (CSharp):

1. public void FindMatches()
2.     {
3.         matchingTime++;
4.         //Horizontal Scanning
5.         for (int row = 0; row < height; row++)//Go through each row.
6.         {
7.             for (int column = 1; column < width; column++)
8.             {
9.                 //Debug.Log("("+matchingTime+") "+column + ", " + row + " is " + allDots[column, row].tag);
10.                 if (allDots[column - 1, row].tag == allDots[column,row].tag)
11.                 {
12.                     comboCounter++;
13.                     if(comboCounter > 1)
14.                     {
15.                         doomedDots.Add(allDots[column - 2, row].GetComponent<Dot>());
16.                         doomedDots.Add(allDots[column - 1, row].GetComponent<Dot>());
17.                         doomedDots.Add(allDots[column, row].GetComponent<Dot>());
18.  
19.                         foundMatch = true;
20.                     }
21.                 }
22.                 else
23.                 {
24.                     comboCounter = 0;
25.                 }
26.             }
27.             comboCounter = 0; //If I don't put this here two wrapping match 2s will make a match 4
28.         }
29.  
30.         if (foundMatch)
31.         {
32.             CollectMinerals();
33.             Dot.machable = true;
34.             //TODO
35.             //Check for matches
36.         }
37.     }

Dot Update that makes it move when it's coordinates change:

Code (CSharp):

1. void Update()
2.     {
3.         targetX = column; //Will change if the column is changed externally
4.         targetY = row;
5.         /*If the column has been changed by another script and does not equal the position anymore*/
6.         if (Mathf.Abs(targetX - transform.position.x) > .1)
7.         {
8.             tempPos = new Vector2(targetX, transform.position.y);//Lock sights on new position
9.             transform.position = Vector2.Lerp(transform.position, tempPos, .4f);//Go to that new position
10.  
11.             if (Mathf.Abs(targetX - transform.position.x) < .1 && machable)//If it did it's job, check for matches
12.             {
13.                 machable = false;
14.                 board.allDots[column, row] = this.gameObject;
15.                 board.FindMatches();
16.             }
17.             position = new Vector2(column, row);//This is required for FallIn
18.         }
19.  
20.  
21.         if (Mathf.Abs(targetY - transform.position.y) > .1)
22.         {
23.             tempPos = new Vector2(transform.position.x, targetY);
24.             transform.position = Vector2.Lerp(transform.position, tempPos, .4f);
25.  
26.             if (Mathf.Abs(targetY - transform.position.y) < .1 && machable)
27.             {
28.                 machable = false;
29.                 board.allDots[column, row] = this.gameObject;
30.                 board.FindMatches();
31.             }
32.             position = new Vector2(column, row);//This is required for FallIn
33.         }
34.     }

If you need more code to understand the issue I'd be happy to add it.