Any UK winner can opt for anonymity when collecting their prize. The National Lottery give financial and legal advice regardless of your choice. Only around 20% opt for publicity.
The fact that there's a person with a different name than a lottery administrator shouldn't give you any additional confidence that that person isn't just a fake identity of the lottery administrator. Based on the stated facts, 0% are known for sure not to be fake identities of lottery administrators.
For example, family members of giveaway administrators are generally prohibited from winning, but how are you supposed to know who they are?
Any UK winner can opt for anonymity when collecting their prize. The National Lottery give financial and legal advice regardless of your choice. Only around 20% opt for publicity.