The MACD has not failed to turn negative. it is negative right now.
The MACD has been negative on the dailies for quite some time (since October 24th or so) . People here have let 30% of the pricing escape them in this stock while it was breaking down.
You need to adjust your model's programming.
We are apt to shut our eyes against a painful truth... For my part, I am willing to know the whole truth; to know the worst; and to provide for it. --Patrick Henry, Patriot and Hero of the American Revolution