http://www.footballzebras.com/2018/01/21/championship-liveblog-jaguars-at-patriots/#liveblog-entry-53631
13:53 | 4th qtr. Looking back to the fumble recovery by the Jaguars early in the 4th quarter, there is a question as to whether Myles Jack is down by contact.
Whenever a ball is stripped from a player in possession on the ground, it is down by contact and no fumble. In this case, the ball was not in possession but taken from an opponent’s hands, so this is deemed as “contact” by the Patriots as Jack begins to take control.
Is it possible that there was no hand-to-hand contact? Yes, but there is no way that can be perceived, so the officials are instructed to treat this as down by contact.
The contact, by the way, only has to occur when a player is beginning to secure the ball. It is held until the player finishes establishing control, and is dead at that point.
This was correctly ruled as down by contact on the recovery.