The closest thing to ‘subject matter knowledge’ I have is a fair amount of reading the news; and some playing of the Rainbow Six games back in the day; but I imagine that, in a situation where the hostiles are inside the building but don’t egregiously outmatch the security forces converging on them, they’d be inclined to avoid spending too much time staring out the windows; since doing so carries the risk of starting a sniper duel you aren’t going to win, and/or makes you vulnerable to getting shot by police protected by whatever bearcat-equivalent light armored vehicles the local security forces prefer.
Unless they are willing to just level the building, it offers a lot of internal choke points and enough visual cover(possibly actually-bullet-resistant cover as well, depending on construction materials) to make storming the building a really, really, hairy prospect for the attackers; but trying to defend the building from the windows, while still offering you an elevated, somewhat covered, position; puts exposes the defenders to the probable numerical and equipment superiority of the security forces.
You want a really good stick there. Super long, skinny, and doesn’t snap when it’s being stressed like that? I don’t know where to get such a stick, and if I did, how much trust to put in the stick. That’s a fine stick they have.
Maybe old-style ones, modern pole-vaulting poles are way more flexible and springy than the OG wooden ones. They could probably make something equally stiff, but the demand from tactical response units is probably even smaller than that of competitive pole-vaulting.
