Possible Dupe Glitch involving Sanctum

Picked up two uniques maybe 5 minutes prior, put them away into stash. Went to friend's sanctum and ran till first boss, he died from no more resolve at the exact moment we killed boss and when i checked my inventory again, i had new versions of the same two uniques i had obtained earlier in the same spots i moved them to.

Correction, i have been informed that my guildmate had put one of each of said uniques in the guild stash and i am likely just confused.