Twinthread Incorrectly HQing as x2 NQ Threads?

[Pofo]

I'm not quite sure if this is a bug, or the natural result of a Weaver's offhand tool, but here's my story. Today I wanted to take a shot at a Vanya Robe attempt, so I purchased 6 Crawler Cocoons +1 and 3 Effervescent Waters +1 (roughly 1,700,000G), and I had someone proceed to make them for me. All 3 attempts were HQ, she was not offered a chance to double down and her character did the HQ animation... Now here's the thing, instead of getting a +1 Thread, like you're supposed to get, the HQs were yielding x2 NQ Threads. We made a thread +1 the previous day just fine, but we're both fairly sure that we used the main hand tool for it, this time we used the offhand tool.. because one would assume you produce thread better in a spinning wheel.. no?

So the question I guess would be, is this a glitch, or does the weaver off hand tool prevent HQ results in exchange for quantity? I've tried looking information on this up but it's yielded no results. If this is a glitch, how do I go about getting compensation for my loss of materials? I tried contacting a GM in game, but they were about as useful as colon cancer, and had nothing for me but a worthless auto-response.

Also, before someone mentions it, there's no possibility of foul play, because not only do I have the results in my chat log, but the crafter in question shares a bedroom with me so I watched every synthesis take place.