Where was Firenze?

[Bee chase]

No: HPFGUIDX 145158

Luckdragon:
I do not recall hearing much about Firenze in HBP, but it was 
indicated that he was still teaching at the time. Where was he 
during the fight and flight scenes? Knowing what we do about Firenze 
is it possible he slipped out of the castle and helped DD? A few 
points to consider:

-Centaurs know what the future holds by reading the stars.
-Firenze told Harry about the use of Unicorn blood to save someone 
close to death until they could be given a better potion(ie:Elixer 
of Life)
-DD had fresh blood trickling from his mouth.
-Firenze chose to side with the humans against LV and was willing to 
do things other centaurs would not do in order to help.
-If one consumes unicorn blood, but is not involved in the killing 
is he still cursed to live a half life?
-How likely is it that DD(having been Nicholas Flamel's partner)
might have some of the elixer of life in his or Snapes private 
potion collection and possibly some unicorn blood as well?
-Nicholas Flamel took the Elixer long enough to live over 600 years. 
Just holding the stone saved Harry from dying in his fight with 
LV/Quirrel. Is it possible a vial of the elixer could restore DD to 
his previous state if someone had administered Unicorn blood to him 
to prevent death.