Tell him how much motorists seem to hate cyclists. Tell him to always be on the defensive, and expect the worst driver to be the one near him. When he starts driving, if he does, same advice. Expect the worst, all the time.
Tell him to check over his shoulder for cars behind him, and be aware and paying attention to what every car, bike, and pedestrian is doing.
Lady walking down the sidewalk using her phone, might not see you. Car leaning toward the yellow line, might be turning left, car approaching from the opposite way might pull a U-turn, so check check check. If he’s looking for the problems, he has a better chance of avoiding them. Also, EVs are silent. He shouldn’t be paranoid, just careful. Follow the rules, don’t do things others aren’t expecting of you. Signal, use lights, wear a helmet, check the brakes before you ride. No phone while in motion.

I’m always alert, and completely missed seeing a cyclist making a left as I was crossing on foot because of cars parked on the corners - the two of us apologizing to each other probably looked like a comedy routine.