I am reluctant to get into parsing this headline. My translation is that Hamas was using the building as a shield, believing the IDF would not fire on their position so close to that building (or a hospital, same thing, same horrid mindset of Hamas). Cog is right the article doesn’t say Hamas was *in* the building. But Charles didn’t say Hamas was *in* the building either, just using it, Charles took the headline from the headline as it appeared on the page.
And AFAIC I said too much already.