Soft tissue swelling develops over a period of hours.

Bruising over a femur is, in fact, not especially common and when it appears it tends to appear later rather than immediately, because the bone is deep and surrounded by a great deal of muscle.

That surprised me and it is the single most counterintuitive fact in this entire account: the mark I found at ten twenty-two in the morning was, if anything, evidence against the injury having happened in the previous forty minutes.

And periosteal reaction — the first visible healing on a film — begins to appear at roughly seven to fourteen days, and there was none.