So having been on the other end of the coin it has been rather disheartening. I popped a positive test back in August. I was and have remained asymptomatic. In a case of due diligence I contacted Alaska so that contact tracking could be performed. The response I got was "Oh sad that you are positive, we look forward to you flying again". They also stated that contact tracing would be performed by local health authorities.
Due to the nature of work, I was involved with three state health departments with different guidance. One wanted the travel history but only for the flights that arrived and not departed the state. Another one wanted only a list of contacts I had 48hrs prior to getting a test done. A third was "oh you work in healthcare, yeah just wear a mask and get back at it"
So the long and the short of it is, If you think you know where you got it from, you probably did. Wear a mask, wash the hands, take appropriate steps.