Actually, I did not say that. However, the United States Supreme Court did, in
Reid v. Covert
In Italy's legal system, the multiple-trials custom lets everybody know right up front that a person can be found guilty after being found innocent. If the United States didn't like that custom, it should have objected to it before or while Amanda was being tried. I don't see how it can let the whole process play out, all the while giving it tacit approval by saying they were keeping an eye on things, and then come back later and say they didn't like it.
As Machiavelli (and possibly the Italian court) would claim, if they didn't like it, they should have said something.
However, my original point is that it should not have to get to the point of citing Amanda's rights under the US constitution, when her rights under the Italian constitution were plainly breached.