I wouldn't go as far as to say "horrendous". It happens every game and it is a bit of a farce now. The first corner. Rough and tumble in the box. The ref blows his whistle and tells off the players and then it continues for the rest of the game. Just about happens in every game.
Was very impressed with Celtic's pressing game. Reminded me of the Charlton era at its best but with Celtic also playing football when they got the ball. Should have been 1-1 with the dreadful header miss in front of goal. Enjoyable match to watch. Perhaps Celtic should have played for the draw and tried to snatch something from a corner or set piece but that's hindsight.