It is not hard to miss a little dirt when you do a cleaning. Anybody can have an off day. A little chunk of something stuck under an extractor...then it gets knocked out while shooting. Stranger things have happened. I wouldn't sweat one experience like that. I doubt that 1500 rounds is going to wear out anything on a Ruger. We are not talking about a Jennings here.
Romans 1:16 I am not ashamed of the gospel, because it is the power of God for the salvation of everyone who believes: first for the Jew, then for the Gentile.