It's not quite clear yet whether the problems is in fact caused by rotating a model but you may find occasionally that models 'break' in Quake 4 edit and become un-selectable as a result; left mouse clicking or drawing a brush around the object and trying to 'Select Inside' don't work.
The only way to remove the entity is to manually edit the *.map file by opening it in NotePad (or similar text editor) and then finding and deleting the entity data. Version save and then open the map in the editor; you should find the broken model is no longer present.
Models appear to get broken doing the following (although not limited to);
- Manual rotation on too small a grid.
- Ctrl+K connecting the entity to something.
- Shift Click multiple selections.
