Definitely the RNG Gods smiling on you. Haven't seen back to back Sacreds but I've seen a clanmate get both a Sacred shard and a Lego Book from the same NCB chest.  

Gratz on the back to back Sacreds though. 😁

no correlation between damage done in CB and loot quality, just some good old fashioned luck coming your way :)

I kept daily records for CB rewards, doing double chests on brutal/um/unm daily for about 9 months.  The average sacred per month were around 9.  But ranged 5-15.  There were numerous instaneces where I pulled 2 in the same or consecutive days, even 3 on the same day once.  There were more instances than I care to remember where I didn't pull any for 10 or more days.  There was never appearant correlation between damage dealt and rewards.

let me think about it, i taught about it..