The teenager lay in an induced coma in a Sydney hospital, his neck and spine broken, his lung collapsed, and his brain with potentially irreversible damage.

It was just days since Mr Han and his friend Navjot Sekhon, 18, were allegedly struck by a ute as they walked on Henty Street, Braddon, about 5.30am after a night partying with friends.

Disturbing CCTV footage appears to show the ute approach them from behind, hitting them and then driving from the scene.

The driver later handed himself in after seeing media reports of the crash, but police are continuing investigations and have not yet laid any charges.

Mr Han's situation was particularly grim.

He was airlifted to specialist care in Sydney with three broken vertebrae in his neck, one in his spine, and possible brain damage.

For four days he lay unmoving as his friends and family, including his carer, Mayling Haywood, waited in fear.

But, in a strange turn of fate, the teenager woke from the coma on his birthday.

That amazing development, described by those around him as a ''godsend'', has been matched by an equally amazing process of recovery.

Ms Haywood, who is affectionately known by Mr Han and others as ''Mumma May May'', has helped look after him since his parents returned to their home in Burma.

She was with Mr Han in Civic just before the alleged hit and run, but had taken a taxi home.

''As soon as he came out, we were up [in Sydney] and he had movement in his right arm,'' Ms Haywood said.

''He's recovered extremely well … he actually remembered everythingso that was a great sign that there was no brain damage,'' she said.

His friends and family were initially concerned at his sudden emergence from the induced coma, worried he had woken too early and before he had fully healed.

''We were pretty excited, but we were shocked, too,'' Ms Haywood said.

''He was saying, 'look, Mumma May, I can move this', and he could lift his leg … so he was showing us there was movement there.''

His recovery has gone from strength to strength since, Ms Haywood said, and the teenager is undergoing physiotherapy to help him regain the use of his legs.

It is still unclear whether he will make a full recovery, but Ms Haywood said the doctors had advised there were no apparent signs of permanent brain injury.

Now, Ms Haywood is organising a fund-raiser to help his parents stay by their son as he goes through a long and painful healing.

Friends and supporters plan to hold a function at Charlie Black in Manuka on Sunday from 2pm.

The event, titled ''Burma's back on his birthday'', will include a barbecue, live music, and an auction.

Anyone wishing to donate funds to assist Mr Han's recovery can make a deposit to a St George Bank account: BSB 112 879, account number 485 984 158. Donations can be taken only for the next month.