This has been mentioned in the past, and it's based entirely on the fact that what character signed up and which character showed are different. The system isn't looking to see which account is associated with the character, only which character showed up, and which character signed up.
I don't think I'm explaining it correctly.
The character that signed up, showed.
I associated the DKP of the one that signed up and showed to a different character.
Now it shows that the different character showed, when in fact it was the character that signed up.