Generating backspin on a long pimple chop

 hey Alois I was watching the 2015 Chicago open final on YouTube between Gionis Panagiotis and Jean Michel saive. I recall you saying in the previous question answer that you cannot generate your own backspin with long pimples, but how come gionis is generating such heavy backspin when he chops in this match? Even when saive gives him float forehand they still come back so heavy... I could tell that it's heavy backspin because the amount of effort Saive was putting into every forehand, and the forehands that when in the table were not very powerful...