Except that SketchUp does not have any “limbo” (no active command) mode like AutoCAD.
In SketchUp there is (or should be) always some kind of tool set as the active tool. (There are times when this doesn’t happen, usually during Ruby code execution, and this used to cause BugSplats. I can tell when this happens, because my system cursors are bright orange, and I see the orange default arrow system cursor over the modeling area.
When this strange “no tool” situation happens the
Sketchup.active_model.tools.active_tool_id == 0 and other tool methods should not be called as crashes could happen.)
Any keyboard accelerator that activates any other tool will also exit your tool (as well as any other.)
So, you were just thinking in command mode which SketchUp does not have.