DNA Testing Question?

Q: I did dna testing for child support and the test said that the man I tested is not the father. My son looks very similar to the man, has the exact same birth mark that he and his daughter has, and when he sleeps he looks just like his 8 yr old daughter. Is it possible for someone to have alot of features/look like someone and not be their relative based on dna testing? Could the dna testing not be accurate?

A: Why not just test all the other men?