Proving that Rice's theorem does not apply to a property
The answer is right but the argument is not sufficient. Try to build a contradicting example as a proof. Describe how to encode each machine into a binary number (can be found in any tcs book). Then choose some random non-trivial property say number of tates equal to 4. Show that there is a machine the belong to the ass and a machine that does not. Finally describe a universal machine deciding the property (which is doable if the encoding is injective/reverseable (which is usually the case). Since the example contradics the theorem it early does not apply here. The intuitive reason is that you defined property in machines and not on languages.