hi suzy sorry your friend is going through this, take it easy, it is still very early days ,I had missing time for three months and its real important that he dose not tax his injured brain, because this can cause more damage, often friends and family with the best intention, hope for and expect quick results . some times they keep people in a coma for this exact reason, trying to use a damaged part of the brain can cause it to destroy adjacent areas, so baby steps is the best way forward , so the docs statements of wait and see is correct, your friend will not benefit from knowing to much about possible out comes at this stage , please remember its a scary place he is in just now, but that will change calm support is the order of the day
keep us posted and if your friend needs support when he is up to it, he can always log on, I am a kiwi there is little support in the community there, I am overseas at the mo but check if there is a head injury support association in NZ they will help with his and your concerns, also check he gets follow up treatment from the hospital, ask his family to start the process with ACC it is a battle that he will need help with
my best wishes one day at a time