This is something I noted while I had cheats active with the option to show current hitboxes.

Any lweapon of type reflected magic (the ones in question were generated via script) has a rectangular hitbox that seems to be rotated 90 degrees relative to other lweapons.

Example:

Normal Hitbox-

+-------+
|-------- |
+-------+

Reflected Magic Hitbox-

+----+
|-----|
|-----|
|-----|
+----+

The shape of the hitbox is not being adjusted by this script in any way.
I should also note that the shape of the hitbox seems to vary with other lweapons, though square and horizontal rectangle shown are the most common.