Howto: Select ship for placement. Click+Drag as though selecting orientation for ship. Release drag over UI element, like the ship inventory or the menu at the bottom. Click to place the ship out of bounds.
This only seems to work when selecting ships for placement fresh from the ship inventory at the left. Placing ships inside of terrain or overlapping one another is also possible in this way, presumably for the same reason.
Nice...
Only happens when the mouse up was getting eaten by some UI elements.
I've made sure to update the build ghost position prior to attempting to build the ship, so these cases will be fixed in the next build.