HELP!! Dumbledore & Fawkes healing power QUESTION

[paul pagano]

No: HPFGUIDX 168128

Hi everyone!

I have been reading aloud HBP to my partner on our
long drives to & from New York City and upstate NY!  
He loved OOTP and is thrilled that I won't have to
fill in the blanks for him after we see the movie this
summer! 

Here's a question that he had that I drew a blank and
could not answer him - If Fawkes and phoenixes have
special healing powers, why didn't DD use Fawkes to
heal his severely wounded hand??

Help?!?! Is there something I missed in HBP?  We are
only halfway thru the book and even tho I have read it,
I have stalled his qiuestion with - YOU HAVE TO WAIT
AND SEE.... but honestly I do not have an answer.

Please help! ANYONE??

Paul