LibreOffice had (has?) a similar strange race condition when typing. When the computer was acting slow and LibreOffice Writer was lagging, the Finnish layout's characters äöå would jump to the front of the typing queue somehow. So if I typed "menkäämme", I might get "äämenkmme" when LibreOffice finally renders the typed text. I don't know if it still occurs but it was really annoying and I always wondered how on earth it could happen.