When Uke overcommits in hipthrows (goshi-waza), Tori can defend by stepping to the side (tai sabaki) to avoid the throw and during that action Tori can pull at the sleeves or lapel (depending the side of grip and side of the tai sabaki), further breaking the balance of Uke, enforcing the kuzushi (losing of balance) and guiding Uke to the ground.
When Uke overextends in hip throws (goshi-waza), Tori can defend by stepping sideways (tai sabaki) to avoid the throw.  During this movement, Tori can pull at the sleeves or lapel depending on which side of the grip and the side of the tai sabaki they are using to break Uke's balance and force them to fall.