They probably had a mistake and just did it accidentally but we don't know if there's deep intention about those duplicated application.
This must be the concern for managers because most of them can't even check each of their participants.
I saw some members complaining on the bounty thread that some scammers use this trick to confuse the bounty managers and give the tokens to the wrong eth address.
Hence i just suggest this tip for bounty managers to sort out duplicated names.