Does the EPU on the F-16 need to be manually extinguished after an emergency landing?
The Aviationist has an entire article on this: Hydrazine: A Significant Hazard Each Time An F-16 Crashes (Or Fires Up The Emergency Power Unit). It says:


  the impact site of a crashed F-16 can be extremely dangerous and one
  of the main hazards is Hydrazine [...] When activated, the unit
  provides emergency power for the aircraft’s systems in the case of an
  electrical failure: in case of flame-out, emergency power generated by
  the EPU is designed to give pilots the time they need to land the
  aircraft safely. And, the EPU is fired up by Hydrazine.


And (emphasis in the original):


  the toxicity of H-70 is such that special procedures must be used to
  manage crashes as well as in-flight emergencies that involved the EPU
  or hydrazine leaks.


The whole thing is too long to quote, but the emergency response team certainly takes some very specific actions to deal with the hydrazine. They isolate the aircraft, give the crew breathing masks to get them away from it, check for leaks and then clean up if needed:


  As soon as the first assessment has been completed, the first team is
  replaced by a “response team hydrazine” composed by 2 Italian and 1
  American operator, equipped with special overalls (Level A, since risk
  of contact with the liquid is higher), that clear the leak along the
  track followed by the aircraft from the runway to the parking area.