@Weepixie
It's complicated....but...
Philippa's main argument rested on the discovery of a document about Margaret of Burgundy (Edwards IV's sister) giving support to an armed attempt to put one of the princes (I think, Edward,the older prince) back on the English throne in 1487, when he would have been 17. The fact that she was his aunt was irrelevant though, because she left England in 1468, 2 years before he was born, so she would not have been in a position to recognise him or to confirm his identity. She may have been very keen to oust the new dynasty in favour of the Yorkists, though, so would have been motivated to help raise troops in order to destablise the new Tudor regime.
The programme focused on the authenticity of the document, which is one thing, but completely ignored the point above (Rob Rinder - call yourself a laywer???)
Since the programme was made, another Channel 5 documentary focused on a number of fascinating and tantalising discoveries which throw light on the Princes in the Tower mystery. It was called 'Princes in the Tower: A Damning Discovery. I think it's on YouTube and may still be on 5 Catch up.
Thomas More, writing about 30 years after the event, says that Sir James Tyrell was tasked with 'disappearing' the princes and that accordingly, Miles Forest and John Dighton were dispatched to do the deed, which they did by suffocating the boys in their sleep. There have been attempts to discredit More as a Tudor propagandist, but historians agree that his account has the ring of truth about it, especially in the detail.
It's recently been discovered that when More was on one of his foreign embassies one of his servants/secretaries was the son of Miles Forest, giving him a direct connection to one of the perpetrators.
And also - a will of Sir James Tyrell has been discovered in which he bequeaths the gold chain belonging to Edward V (I think he actually describes it as such) to his heirs. How else could he have obtained this if he hadn't been involved in the assassination? It might have been given to him as a reward by Richard III, or he might have just held on to it after Richard's death.
There's more but I'd better stop there! Hope this makes sense. I recommend the Channel 5 documentary!