It wouldn't surprise me. I have 2 Hard Crota completions and have gotten everything besides the sparrow and fang. There's guys out there that have run it 50+ times and not get that lucky. And How's about tossing in a tl;dr saying: It's your belief that each player has an individualized loot table that has different weight for drops. There are also those that get extremely lucky and get their low-weight items.