Seems like I understand why..
Here, I just
clicked attack few times without waiting the page to be refreshed. So, after the opponents will be died in
one page refresh.. I try to save my time..
When the page refreshed, sometimes I might have already killed that person with 10 clicks but I clicked 20 times. So, what happened in that person
it showed them that I killed him/her 10times even though I just killed him/her
once (which I'm also sure that even though it
showed you that I killed you
ten times but
only one that is recorded in the leader board).
Check your leader board again..

I think the error is in the message.
Here the picture:
this picture show us that I've already beaten the guy but I still attack and that guy got lose twice..

