I take all submitted entries on LDS site with a degree of sceptiscism.
Many of these entries were done many years ago, US people looking for their UK ancestors, no visits to UK, just very scant records available and they have just added people to their families 'cos right name, age etc., well we all know how accurate that type of supposition is.
Justkia - I think that a 'genuine' mistake is being very generous on your part.
I have seen people born in UK, marry in UK, then go to the US, but come back to the UK to give birth to every child (as many as 10 times!) and then their body is brought back for them to be buried in their local parish church.
Sadly the LDS records which are submitted are a guideline which needs in many instances a great deal of accurate research.
The object of the LDS church is to baptise every person who has died into their own church. Which they do in batches. Eventually we will all be baptised into this church so as to enter the kingdom of heaven!!!!