why is this draw because of insufficient materials

White to play, and mate in 4 moves.

I have a whole thread on this dead position problem, while it is very rare, that position you posted actually fits into a simple algorithm I devised that could probably be programmed into Javascript and detect it is a draw. The algorithm is:

1. Alternating Locked Pawns Same Rank (numerical values to where the pawns are could be assigned to determine if the pattern is truly locked, and if the squares that the pawns occupy and control form a continuous straight line, we know the kings can't penetrate)

2. White king below rank with white pawns

3. Black king above rank with black pawns.

4. Both sides have bishop on the same color as their pawns.

5. No other pieces.

This would take into account alot of variations of that position.

White can not timeout in this position.

Either it is Black's turn to play (and of course he can mate on the spot) or it White's, and the game is already over (stalemate).

A beautiful smothered mate zugzwang with only one knight left on the board.

Ne2-g3 also works.

What happens in a USCF tournament when 'insufficient material' can demonstrate a forced mate but opponent lets his clock run down? Does the arbiter overrule or is it a draw?

oh ye srry i didn't put a position where white was in zugzwang

In USCF, supposedly if the player can demonstrate a checkmating position or a forced mate, that over-rides the draw and the arbiter will give him the win. In FIDE, if any checkmate position in theoretically possible, even if not forcible, or so absurd your opponent would have to consciously help you win, it's still a win for you, even if you have 1 pawn and your opponent has 9 queens, you win if he runs out of time. This site uses a lesser version of USCF where just the piece count on one side is used, regardless of it there are forced or inforcible checkmate positions.

So in simpler terms:

FIDE: If any checkmate position is possible

USCF: If the knight or bishop can force the checkmate

This site: Draw regardless of if mate is possible and/or forced.