I don't have an answer to the question (which is a developer problem, there's nothing I can do about it) but I'll explain what happened:
- The question was posted on Meta.Electronics, and got no answers for a while because I was in lab.
- 20 minutes later, it was cross-posted on Meta.Stackoverflow, where it got an answer from ChrisF.
- Half an hour later, the post on Meta.Stackoverflow with the answer from ChrisF was migrated from to Meta.Electronics. ChrisF, xralf, and Pekka all have user accounts on Meta.Electronics, but no usernames were associated. Bobby does not have an account, so his comment does not have an owner.
- I noticed the lack of association and duplication of the question, so I closed the question from Meta.SO as a dupe of the earlier question. The earlier question had an associated username.
- I merged the migrated question with the earlier question, which moved ChrisF's answer over to the earlier question, so at least part of the post had an association.
The problem was also noted in the comments to ChrisF's answer and in a top-secret chatroom, message ID 3640824.