Ambulance at the Chiropractor's Office

Today while driving home, I saw an ambulance parked in front of the chiropractor's office. I didn't quite see who, but the driver was just shutting the doors, and then walked around to get in the driver's seat, lights-a-flashing. As one who winces at the thought of visiting a chiropractor, I mused a bit to myself, thinking about the menagerie of stories that could have evolved from that singular event, and determined that I MUST include that in a book someday. After all, real life makes the very best stories.

So, here is my question for you:

Did the ambulance show up because:

A. The doc tweaked so hard on someone that they could not stand or walk afterward

B. While watching the doc tweak someone's spine, an onlooker passed out

C. A person with a previously fractured bone showed up and SNAP!

D. Other (fill in the blank)

You see, none of these sound even remotely positive, and still I count myself fortunate that I have never visited, and hopefully will never visit, a chiropractor. If I only had a bit more time on my hands, I would peruse the ensuing court cases over the next several months to determine exactly: what was the story behind that ambulance at the Chiropractor's office?

Very sadly, I did not capture the epic moment on my iPhone because I finally got a clear shot at this lovely old home, just for you: