Just throwing this out there, but... are those getTypes necessary?
For example, love.physics.newCircleShape(1):getType() returns "circle", but love.physics.newCircleShape(1):type() returns "CircleShape", so are the physics getType methods kind of redundant? And the type of a Source can already be determined by isStatic, and for Canvases, um, isHDR? :D I have no idea.
As well as the mentioned getType functions already existing, maybe the type of a object isn't really part of the object's state, so it's okay that it's different, or maybe even good that it looks different.