If you fire at a window, and only at one particular pane of the four, the other three shatter as if they're being shot at (complete with bullet holes as well) too.
You should only have one pane shattering, the rest may crack at the most.
Anyway, all four panes end up breaking even if you continue to shoot through one with a bullet hole already made.
Hit any one of the four panes, and keep shooting at it.
Even if this is one pane with four wooden divisions, the other four divisions shouldn't appear as they've been shot through (unless they have).
Mass closing ancient tickets with no activity for > 12 months; assume fixed or too trivial.
If this issue is still relevant in current dev build, please re-post.