The Kha'zix and Vladimir are duo queued, both on their secondary (not auto-filled) role, and trolling. Looking at their match history over the past month, they have done this every single time they didn't get their main role, with over 200 games.
Neither the system that's supposed to stop trolling on off roles or catch intentional feeding has caught them, and I experience this type of bullshit in probably 1/6 games.
What steps are even in place to catch people who don't try on off roles? This makes it seem like there aren't any.