Self-isolating
Either he made the decision to sit by himself or the other passengers on the plane played a game of rock-paper-scissors to determine who would have to switch seats. Either way, he was forced to sit by himself. The correct approach might be either of the two approaches. It’s plausible, given the unprecedented nature of the situation we’re in right now.

He’s being too careful about his health to keep his friends from getting sick and to keep in touch with them. This can happen because these things have never happened before.If they don’t take the time to learn how to read lips, they and their friend will either have a very awkward conversation or, even worse, won’t be able to talk to each other.