They were on the 20 with 20 seconds left and 0 timeouts. If you're the UK DC you just put guys inside the 10 and tell them to protect the endzone.
If you take a sac, you might not be able to get a FG off. If the snap is bad, same thing. Maybe your guy makes a play, but you gotta thing it'll be into double coverage.
It was a bad call...