In reply to partz:
You might have a real injury which just a delayed response., but it could also be pain that is induced by an external stressful event/ and or person.
Watching your video would count.
Other examples where you body over reacts would be
- Feeling faint as a result of a minor scratch
- Palms sweating when you watch a stressful climbing video
- A pain that appears and disappears without reason
This can happen because it is your brain decides whether or not you feel pain and by how much, not your injured body part.
It would be interesting if anyone has come across other examples of this or has found some research.