Why is there confusion about George Harrison's birthday?

The date on George Harrison's birth certificate is February 25, 1943.
In the early 1990s it was reported that a new hospital document had been discovered. This, it was claimed, recorded the time-of-birth as 23.50, February 24.
Only it didn't because George was not born in hospital. He came into the world in a very small terraced house, 12 Arnold Grove. His sister, parents and all existing documents confirm that his happened in the early hours of February 25th.
Why the confusion?
Th source of this mysterious non-existent 'document' remains mysterious. The most plausible explanation is that comes from an off-hand remark - or possibly a joke - from Harrison himself. This was then taken up by many reputable outlets, including the the Rock and Roll Hall of Fame.
The Hall of Fame has corrected the mistake, as have most official sources. As The Beatles Bible points out
Some sources list George’s birth date as 24 February, but his birth certificate specified the following day as the true date.
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