I completely disagree. Good storytelling could give all the context we need. Action shots of the TARDIS. A voiceover from McGann (or even Hurt, reflecting on the last moments of his predecessor's life). A weary and traumatised McGann, doing something dramatic as the clock ticks down. Dying at the hands of Daleks or the like. Reincarnation occurring. Hurt saying something like 'in those moments, when all seemed lost, I was born.' Shot of Hurt, looking less traumatised and uncertain than other newly-incarnated Doctors and cut to him doing something shocking that no other Doctor is likely to have done before or since. That's off the top of my head. Pretty sure Stephen Moffatt has had time to write something at least 73,000 times better.