I'm guessing it's a rendering glitch. It's not actually two sacks in one play. The first sack is the previous play. Then the glitch occurs for the last play. You may notice how the down updates from 2nd down to 3rd down. I've had this happen before on a field goal. For some reason, the entire play is displayed visually as just the last moment of the play. So what you're seeing is the end of the play. But it's still going through the time that takes place on the play. So if the play takes 5 seconds to play out, all you will see is the last moment of that play frozen in time as the 5 seconds count down on the clock.
You should report this under Bug Box.