I used to live quite literally two blocks from Sanchez's district. Thankfully, I was on the side of the street where Dana Rohrbacher was my Congressman. Tan's office in 2006 was down the street from my house on Harbor Blvd.
The issue here is not whether or not Tan sent the mailings--it's apparent he at least knew about it. But 1--he lied about it, 2--sent them ONLY to Spanish-speaking households where there are several nationalities, including Vietnamese, Mexican, American, etc., in the district. Had he sent them in several languages to ALL or at least distributed them equally throughout the district, there really isn't much that can be said.
He did something wrong, IMHO. He tried to cover his ass, and he got caught. Right message, wrong delivery.