I doubt that the agents were engaging in sophisticated linguistic analysis. I suspect they just misunderstood/misapplied the policy.

Honestly, if that were the issue, and they’d offer to tag the bag to NRT, that likely would have been good enough. Once ANA got the bag in their possession, I suspect they’d have had no issues re-tagging the bag to BKK at LAX. The only fly in the ointment would be that it’s risky due to current entry requirements to Japan; if they weren’t able to re-tag her bag, I’m not sure how she’d have gotten it at NRT to re-check it there — but, again, she was flying NH F. Even if she hadn’t been able to get it retagged at LAX, when she was met upon arrival, I’m sure the NRT staff would have figured it out.