Well, I called the church right after getting out of class. The secretary was not aware of the issue - hadn't even opened the e-mail, but her response was one of:

1. Mistakes happen (I made a point that it was accidental)
2. If someone's "on it," it's no big deal. (I reiterated that the window was most likely going to be replaced today).

She gave me to believe that I wasn't going to need to think about paying for it, but I'm not going to draw that conclusion fully until the whole incident is well past.

And maybe I need to invest in some Nerf stuff. Though the winds being what they were last night, perhaps even a Nerf soccer ball could have become a glass-breaking projectile.