you could also be off by one sail and forget to take into consideration that the "first" completed sail could have been the last sail of the previous day, just claimed 12 hrs later. i am not saying it is the case but it could be another factor in your confusion.
also many players create alts with similar looking names. in the past for example i have seen players create alts and add an > at the end to for example delete all the previous logs and clear the window. since we dont see the names of the involved players it could be that you are fighting xxx_ , xxxl, xxxI, _xxx| and so on... again, i am not saying this is the case, i am only pointing out the possibilities



