He answered your question in his second line, " . . . gun crime's falling significantly lower than crime in general." Yes, he's comparing violent non-fatal crime to gun homicides. He's making a comparison of gun homicides to general crime, and the rate of change.

His second line started with "So". Meaning that it was derived from the fact in the first line.

The second line doesn't follow from the first as it is implied.

You can't get "gun crime is falling more slowly than crime in general" from that statistic, because "general crime" includes homicides which were removed from that statistic. It is entirely possible that if you add in homicides that overall crime is decreasing faster.