I don’t that’s possible unless it was a false positive. It seems like COVID lasts for around 7-10 days. If he was negative Sunday, contracted COVID Tuesday, and tested positive on Wednesday, that leaves just Thursday and Friday. He would need to test negative on Saturday morning and then Sunday morning.
I don’t think 2 days is enough time…and he’s probably not feeling great either. This is if he IS vaccinated which we don’t know