Those three coloured lines indicate that the game engine cannot find the model (.md3) to draw it in game. Misc_model_breakable stays also in the game as an entity, whereas misc_model is turned into simple map triangles (like any brush) in the compilation process. Thus, in order to show misc_model_breakable, the game needs an access to the particular model (md3).
Then the trickiest part of all: When you installed Editin tools 2, you got a bunch of md3 models along with it. They were unpacked straight into your models subfolder, in their particular subfolders, depending on the map they were originally used in. What this means? And how come they are NOT in the assets? Because Raven used them as misc_models that are, as previously stated, turned into map triangles. Thus they only the textures in the game (they need the models in Radiant, though).
Essentially this mean you can you those models as misc_models as much as you like, but to use these specific models as misc_model_breakables or as model2s in func_static or anything, the user needs those models either by installing Editing tools (if he's no mapper, why should he?) or you must supply them with the level (if Raven gives you the permission).
Hopefully you got something out of this.