European GM and Customer Service Forum Representative Issuntril confirmed in May that when a master looter did not have the required profession when a BoP recipe dropped, the pattern would be unlootable. Issuntril also indicated a fix was complete and would be incoming in patch 2.1. Unfortunately, some GMs and Blizzard reps continued to assure players that master loot was currently working with BoP patterns, not realizing there was a problem when the master looter didn't have the profession in question. On top of that, players who didn't read the European forums were still completely in the dark. Craftspeople naturally noticed the lack of drops, raid leaders pointed to assurances that BoP master looting was working fine, and the battle was on. Master looters and master looting alike took some black eyes from irate craftspeople who suspected they were getting gaffed.
The confusion blundered onward when no mention of either the bug or the fix surfaced in the 2.1 patch notes. Nobody seemed to be able to confirm whether or not the problem had been addressed. Issuntril finally laid the issue to rest, confirming that 2.1 had indeed fixed the bug -- although many non-European crafters still haven't gotten the memo. Let's make it official: master looting is once again a safe option for BoP pattern drops, so let your master looters get back to business. Oh -- and good luck winning the drop!
(Edit: Numerous players are reporting that the master looter must distribute the BoP pattern immediately, without clicking off the corpse to do anything else first. If the master looter closes the corpse/loot box, he may not be able to see the pattern again the next time he clicks in. It's not known if this is working as intended.)