Complex sentence: This rule was in response to New Orleans Saints tight end Jimmy Graham's tendency to dunk the football after scores (bending the goal post after one such dunk) and was previously "grandfathered" as a legal celebration much like the Lambeau Leap.
Split into simpler sentences: This rule was in response to New Orleans Saints tight end Jimmy Graham's tendency to dunk the football after scores. This celebration was previously "grandfathered" as legal much like the Lambeau Leap.