Maybe I'm looking at it wrong but if that's the case the MacQueen tartan and the MacQueen clan crest aren't quite right. Or are they?
One thing to point out, though: the clansman's badge displays the crest of the clan chief, which is part of the chief's arms -- it is not a "generic" symbol for the clan per se. When a clansman/woman wears the badge, it is saying I "belong" to the Chief, who is the head of the clan.

Given that the Irish never really adopted the Highland clan system per se, I'm wondering if the makers of said badge found a coat-of-arms for someone named McSweeney and used the crest as they would a Scottish clanman's badge?

T.