As for suppressive fire..
1. Are you sure they would be aiming at the correct window?
2. People above and below that floor probably walked to their windows to see what was going on. Friendly fire casualties?
3. If they are not shooting at the right target, would he even notice suppressive fire?
They are non-opening windows, and it would be very apparent which were broken for the purpose of shooting. Hitting the right one, an uphill shot at great distance would be a problem, though, especially with a handgun.