So I've seen and have done this myself when you try to qml one person but do it to another player farther off or by accident miss the person entirely. This is because when you press Q M L the person who does it gets no message on if it was successful or who they even did it to but the person who gets Q M L'ed gets told who did it to them.
My suggestion is simple. Could we add a message when we Q M L someone saying "you have elected Bob_the_Terrible_Archer for leeching" Then we know 'okay I elected the right person cool' now you know you elected bob for leeching and not your teammate in the middle of the castle.
If you do elect the wrong person it allows you to apologize and avoid any confusion which random qmling does. But also add in if they do press M in time a message with their name like "Bob_the_terrible_Archer is active after all". The reason for this would be to help prove the sitting by their computer leechers in siege who just m everyone who elects them.