Okay, maybe your editor isn't an idiot, but I wouldn't be surprised if someone...occasionally...might think so.
I belong to the EFA (that's the Editorial Freelancers Association to you - not to be confused with Essential Fatty Acid or Egyptian Football Association or European Film Academy). A benefit of joining this association is the online discussion list, where editors go to ask questions of one another and once in a while, share funny stories or general chit-chat.
Just to give you an idea about what we talk about, in the past two days, there have been 19 emails (and counting) debating whether half-eaten (with the hyphen) or half eaten (without the hyphen) is correct usage in a particular sentence.
These are my people, people.
So what does this have to do with your editor being an idiot? Well, when editors (or me, at least) make suggested changes to a manuscript, we are doing it with a voice inside our head (and you writers thought you were the only ones with voices telling you what to do, huh?).
And I suppose it is possible...just possible...that you think your editor is an idiot for even asking the question, because the answer is so obvious (well, to you, anyway). But we are the ones who obsess over whether or not to hyphenate half eaten so you don't have to.
Just deal with our idiot questions...we'd rather look like idiots in front of you than have you look like idiots in front of your readers.