No tests - no requirement. Fact v suspicion
From listening to what and how it was discussed, it didn't seem that she was implying that the crew refused a test.
If the situation is that the law doesn't require one, or empower the authorities to request one of the crew, it may be a failing in the law that they were unable to eliminate the factor from their investigation. That doesn't necessarily hint at suspicion.
I would like it clarified though.