The Defence always claims that whatever is wrong with you wasn’t caused by them.  It was something else.  A childhood fall.  A long-ago car collision.  The physical demands of your past or present job. A death in your family years ago.  Whatever.

This is the “zombie injury”.  It went away.  It was dead and buried.  Then by coincidence it came back to life when you were hurt by this Defendant.  Fell down her stairs.  Slipped in water at their store.  Had the wrong procedure from this surgeon.  Assaulted by this jerk at a pub.  No, no: it wasn’t this, it was that long-forgotten event. 

Use your common sense.  If you put a match to a candle, it’s possible (in a random universe) that the candle flamed due to spontaneous combustion, ball lightning, or quantum spookiness.  But it’s far more likely the match caused the flame.

I call bullshit on the zombie injury.