It's much more likely to have another .mdl file in the same directory that ends with a "t", but it's not connected to the model itself. For example, you want to precache the file "hats.mdl", but in the same directory there are files "hatst.mdl" and "hatsct.mdl" - in this case the "hatst.mdl" will get precached too, even though it's not supposed to.