Why Moggallana suffered from past karma effects, but Angulimala did not?

Aṅgulimāla and Moggallāna both were Arhants. Aṅgulimāla killed 999. Moggallāna killed his parents in a past life. Only Moggallāna had to face karma? Moggallāna was killed by being cut into pieces, whereas there is no story of much suffering concerning Angulimāla. What is the difference?