I think it was the safe thing to do and probably right based on the percentages.
The odds of fumbling would be around 2% based on the Patriots run game this season. Punt return odds, well Jones didn't return a punt for a TD this season but he has in the past, and for his career you see 1.5% of the punt returns for TDs. Hail Mary plays are extremely rare but FWIW, Flacco's splits show a decent percentage of long passes completed. He was 2 of 11 on passes 41+ yards this season, 4 of 16 on similar passes last season, 2 of 16 the year before that.
Now those are actual plays when the defense might not be expecting them, unlike a Hail Mary situation when the D is lined up and ready for it, so it's not fair to use those figures. But it was enough to make me sweat this thing out to the very last second, and makes me wonder if we should have ran a few plays to kill the clock.
Jones also burned a lot of clock trying to put together a decent punt return which wasn't in his favour with the punt block on. With those 10 seconds, Flacco could have gotten a sideline shot to pick up a chunk and make the throw more manageable.
I'm not sure if it was the right thing or not. All I know is the Ravens played us tough and to the very last second.