Just curious, unless someone was their only contact in two weeks, how can one really know who gave it to whom?
I went to lunch with a coworker on Tuesday, and he tested positive on Wednesday (we drove in my car). My temp was elevated on Saturday. On Monday, I got tested and received the positive test on Tuesday. I know where I got it, even though I was around others. Case investigators and contact tracers are a big help with the deductions of where a person might have contracted it.
If you went to a Trump rally, you might assume you got viral loading for ten or more people (but which ones you wouldn't know).