Allen caught the ball at the one but his momentum along with help from the defender landed him in the endzone. My thoughts were that if a player makes a pick in the field of play and his momentum carries him in the endzone, its a touchback. How many times have you seen this happen and the guy falls in the endzone.
Okay...just read this.
(a) Player intercepts a pass with both feet inbounds in the field of play and his momentum carries him into his own end zone. Ball is put in play at spot of interception.
So the call was correct. Kudos to the refs they got a tough one right.