If you R a target as Tristana that was E-ed with 3 stacks, the E won't detonate from R until the target finishes to be knocked back, resulting in her E damage and W reset to be delayed, getting worse as the R knockback increases by ranks.
1.use E on a target and auto it 3 times
2.use R to detonate the E (easier to notice with W on CD and R at rank 3)
I've tried about 4 times in practice tool on dummies and champions, working every time. It does not work tho, if you R someone in a wall that's too thick to go through, resulting in the knock back ending early and the E detonating immediately (as it should).
As I couldn't find where I could add text anymore, I'll say it here:
look at the 3rd debuff on shyvana, it goes 1,2,3,4, but at 4th stack, instead of detonating immediately, it gets prolonged until shyvana stops being knocked back.