Dear Mr. Artenstein,
There are situations in which "doing nothing" is not enough for a person to be considered innocent. There are situations in which doing nothing is a crime.
US President Franklin D. Roosevelt, for example, was in a position to stop the Holocaust, and he chose not to do anything about it.

This is the situation that ordinary Arabs face today. Some of them are active terrorists and murderers while many of them just do nothing. But in this historical period - doing nothing is a crime. An Arab can only be considered innocent if he does the right thing. And the right thing is to become part of a big "Palestinian Peace Now" movement, that will say "We are sick of being a nation whose flag is murder, whose policemen drive stolen cars, racists who cannot accept having neightbors of a different ethnic group. Regardless of 5% more or less real-estate, we are going to establish a Palestinian coutry that will look like a real country - where murderers sit in jail, where children spend there time studying math, biology and English, so that our new Palestine state will be able to develop a high tech industry, so that investors from Wall Street will rank us as a safe place to invest and develop, where children do not waste their precious childhood time on unnecesssary fight against neighbors who are offering 95% of the west bank".
This is what a real innocent Arab would have said.
An innocent Arab would help arrange his nation to collaborate with Israel against the extremists who destroy the life for both nations.

But, unfortunately, the truth is that the vast majority of the Arabs, even if not actively commiting terror atacks do not do what I just mentioned. And as I explained, in this kind of historic situation, doing nothing is a crime.
As long as the "innocent" Arabs do not collaborate with Israel against the terrorists, but rather consider them national heros, Israel must treat each and every one of them as a potential danger. Israel has no choice. The Arabs do. If only they told their kids: Our future Palestinian state will be small no matter what borders it will have. Therefore, we cannot make good living from agriculture. Our future depends on your ability, kids, to establish high-tech industry. And this can happen if you sit down and study math, and not waste your time throwing stones. Let's ask Israel to help us build this good education system and industry instead of continuing our stupid attempt to destroy those who would become our best helpers.

And as long as these stupid people do not say these things to their kids they are NOT INNOCENT. And this is why this woman had to die. Because she is part of a non-innocent nation. The Israeli soldiers have no alternative. If soldiers let sick women pass through easily, terrorists will disguise themselves to sick people. The only solution is for the Arabs to cooperate with Israel against the common enemy - the terrorists.
And if they don't - Israel has no choice but treating all of them as suspects.