How do Master Assassin, Expert Assassin badges actually work?

[Wazzaa21]

This badge looks buggy to me. I can assure you that I have won quite a few times experts with +500 elo.
As RazorOz already mentioned some of my games.
So I am pretty sure it needs to be fixed or be more precise in the description about what it needs to be done for someone to take it, cuz we can say 100% that doesn't work as it specified.

This trophy is buggy for sure. Look another example. Peartree99 won it by not even finish first but in an abandoned game.

[PaulB-UK]

There's 2 of us who can win this race, neither of us have the award:
https://boardgamearena.com/9/heat?table=597113061

4 of the 6 players are currently above expert level, so you'd think at least 1 of us would get the badge at the end.

I won, and was awarded the badge. 2nd place didn't get the badge, despite 3rd and 6th being rated over 500 ELO after the game.