Whenever you have fogclicker team mate, you get all the advantage of his mh as well and you don't get that why the demo version of mh is forbidden ?
As Astaroth said, it has dozens bugs which make you think player has mh. We're already having blind reports a lot because of some retarded situations (capturing rune once, killed by sunstrike once, getting ganked at rosh etc...) and imagine how much would we have reports for those bugged selections...