[M T]

According to the NCAA rules, it does appear that if an offensive player catches the ball on the 1 yard line, the defender can catch the player in the air and carry him on his shoulder (without ever stopping forward progress) through the endzone and out the back of the endzone before allowing the player to touch the ground, then the pass is incomplete.  If the offensive player's forward progress stops, then the player is considered down and the pass is completed.

The same thing is true on the sideline.  If you catch the offensive player in the air and carry him 10 yards without stopping forward progresss to the side line and out of bounds, it is an incomplete pass.

[M T]

According to the NCAA rules, it does appear that if an offensive player catches the ball on the 1 yard line, the defender can catch the player in the air and carry him on his shoulder (without ever stopping forward progress) through the endzone and out the back of the endzone before allowing the player to touch the ground, then the pass is incomplete.  If the offensive player's forward progress stops, then the player is considered down and the pass is completed.

The same thing is true on the sideline.  If you catch the offensive player in the air and carry him 10 yards without stopping forward progresss to the side line and out of bounds, it is an incomplete pass.