A few minutes ago, I rejected a tag wiki edit (which didn't match the comment) as too minor (a one character change), and seconds after I did so realized that I had made a mistake, since it turns out that one character change will matter a lot.
I assume that this answer applies also to other votes, including this one, but thought it was worth asking.
It'll be in the suggested edit review queue; I suppose sooner or later it'll get enough approves and go through, but it would be nice to now if there's a way to undo my error.
Edit: It looks like it ended up rejected; I have fixed it by repeating the change (but at least the comment now clearly explains why it was changed)