It's possible the sound of the spaceship landing (http://community.livejournal.com/fandomtownies/1422127.html) might have been heard in the clinic.

If so, there might have been some warning before Jack limped into the clinic, right arm around and leaning heavily on Sam, Parker walking on his left. River had pulled the (thankfully) slender and smooth bolt out of his left shoulder cleanly, and the spot was roughly taped.

Jack was swearing under his breath at every step, because now that Emma wasn't around, it hurt.