After playing a Swap Your Hand card should the player draw in Saboteur 2?
Player A should not draw.  The player the card was played on is the one who draws.

Another way to think about it:

Before the swap turn, Player A has X cards and Player B has Y cards.  Player A plays a swap on Player B.  Assuming the deck has cards in it, afterward Player A should have Y cards and Player B should have X cards.

Another way to think about it:

If both players have a full complement of 6 cards, and a swap is played, both players should end up with 6 cards when the dust settles.  Assuming there are cards left in the deck, of course.