Is it too large to open into the room? Does it interfere with furniture in the room when it's open? If you feel it overpowers the room then yes, you should probably make the opening smaller. But, if you paint it vs stain it, the door may not appear so large to you.

I'm surprised he can't return or at least exchange it.

The whole point of bifold doors is to minimize the doors presence in the room. To still have that and a hinged door it would make sense to get two smaller doors and hinge them.
Ron

I like doors that take-up the majority of the opening. I find it maximizes the useable space when I can reach nearly the entire closet. I don't like having a couple of feet of dead space on the sides- it's just too hard to find things when the closet it full.