If he did make it to seven, then he should feel pretty good about it, since Jesus only came up with five when he was asked the same question in the gospel of Matthew, and the last one on Jesus' list is from Leviticus 19:18, not the Ten Commandments (Exodus 20:2-17, Deuteronomy 5:6-21).
. . . if thou wilt enter into life, keep the commandments. He [the rich young man] saith unto him, Which? Jesus said, Thou shalt do no murder, Thou shalt not commit adultery, Thou shalt not steal, Thou shalt not bear false witness, Honour thy father and thy mother: and, Thou shalt love thy neighbour as thyself. -- Matthew 19:17-19
(Notice that the only commandments that Jesus lists are the good ones -- the secular humanist ones that deal with relationships among humans. Nothing about worshiping one god, making graven images, honoring the Sabbath, or taking the Lord's name in vain -- nothing that is about God.)
So let's give Westmoreland a break here. If he couldn't name all the ten commandments or named a few that aren't in the Big Ten, then so what? Not even Jesus could name them all correctly.
As Westmoreland's press secretary said, "I challenge anybody outside of the clergy to try to (name them all)." Both Jesus and Westmoreland failed that challenge; but then, they're not members of the clergy.
Here's a fun video about the Ten Commandments numbering problem.