To give you a flavour of the contradictions of dates in even a relatively major event such as the purchase of Bantry [Blackrock] House in the mid-18th century, which is really where the whole story became airborne, compare such details from three reputable websites (Egerton Shelswell-White himself thought it was in 1730):
The original house, a five-bay three-storey building, was built by Samuel Hutchinson around 1720; called Blackrock, it forms the nucleus of the present Bantry House. In 1746 it was acquired by Richard White, a farmer from Whiddy Island who had amassed a fortune from pilchard-fishing, iron-smelting and probably from smuggling.
Bantry House (originally called 'Blackrock') was constructed in about 1700 on the South side of Bantry Bay. In 1750, Counsellor Richard White bought Blackrock from Samuel Hutchinson and changed the name to Seafield.
1699 Captain Richard White and family live on Whiddy Island
1701 Richard White (later Counsellor White) is born on Whiddy Island
1764 Richard White (Counsellor White) purchases Bantry House (then called Blackrock House)
1767 Birth of Richard White (later First Earl of Bantry)
Furthermore, an (apparently) exhaustive historical record of the White family's property transactions fails even to mention the purchase of Blackrock House at whatever date.