In meetings, sometimes when there is an attendee that is not supposed to be in the meeting, and you try to remove them, they are unremovable.
I have seen before where a code/script was developed the forced removed an attendee.
(Even if they were a cohost & you were a cohost.) *Only a host should be able to remove a co-host*
I'm not sure if the script un-cohosted the user first, then removed, or just brute force removed. I do know the user saw the pop up saying the HOST removed them.