Well, your friend is wrong. There is a considerable difference between “saving a life” and “not killing someone”: it’s not like the tractor driver was being asked to save Rachel Corrie from a burning building; all he had to do was not run over her. There is also a considerable difference between knocking down a house and running over a human being. By your logic, someone protesting against police brutality in the US has no cause for complaint if a cop shoots him dead for disobeying an order to disperse.
Also, what “group” are we talking about here? The protestors were not demonizing all Israelis; there are considerable numbers of Israelis who oppose the destruction of houses, and some who are actually part of the protests.
Also, having looked at the website of the International Solidarity Movement, under whose auspices the dead woman was protesting, i can find no evidence that any “group” is being demonized. There are claims about the use of force and violence by Israeli troops, and assertions regarding the illegality of these actions, but the type of demonizing you allege is not to be found. Nowhere is it claimed that the Israelis, or even the Israeli armed forces, are inhuman. The ISM simply states that it believes in the right of Palestinians to use force to resist Israeli actions, but that the ISM’s own tactics will be non-violent.
I’m not claiming that the driver intentionally ran over the woman. I wasn’t there, and am perfectly willing to believe that it was nothing but a tragic accident. But implying that this was suicide, and/or that she somehow deserves no compassion is, IMO, pretty repugnant.