Technically from a rules perspective, one could rule the opposite.
The goblin dies. He does not have another turn. So the helped attack did not occur before the dead goblin's next turn, hence, it does not get advantage.![]()
Hmmm. Maybe. I kinda imagined it as the following (minus the specifics):
Larry: woowoowoowoowoo! (waving hand and then pokes bag guy in the eyes)
Bad guy fatally stabs Larry
Moe stabs bad guy in back before bad guy has a chance to fully recover from the distraction.
Or any of the movies where someone distracts the bad guy before getting wasted. The hero still gets the chance to stab/shoot the distracted bad guy.