[tradition]

■Any kick crossing the goal line is automatically a touchback; kicks cannot be returned out of the end zone.

My interpretation (not an official) is as follows: If the ball crosses the plane on the kick it is a touchback and cannot be returned. However, if a player catches and is in possesion of the ball before the ball breaks the plane then that player can advance even if he/ball then retreats beyond the plane.
ie. Once the receiving player has possession of the ball, the 'kick' part of the rule no longer applies.

For one and maybe both of the questionable FS returns, the ball appeared to cross the plane before the FS player was in possession - a clear touchback IMO.

No kidding. But why argue, Highlands won inspite of the refs.