Discovered that there was a Wand of BlastWave lying in the floor of floor 14 right as I was ascending with the amulet...
Not that I needed it (got a good armor early on and just upgraded it and... Well, if you've ever played SPD with a +13 plate armor you know that hard doesn't enter on its synonyms list) but still, the best wand in the game just laying around? A gnoll probably dropped it after I killed it without even noticing...
Yes, a shaman dropped it, thats certain, but it couldn't be while I was ascending, it must've been while descending; as monsters while ascending drop no loot. The chat log of an enemy dying isn't related, as that happened while ascending.
I must've missed it while descending.