This is because the rep cap eats the down votes in any answer of yours you linked.
A bit explanation:
- you've posted an answer.
- you got a down vote.
- you have reached the rep cap and exceeded it (i.e. 200 reps from up votes per day)
- you delete your answer, but the rep for the day you capped is recalculated, you get the down votes again recorded, but they are compensated by the up votes you got that day after reaching the cap.