Well, a few years ago, I was on a bus, and the driver braked very suddenly. I was thrown against the front of the bus, and could hardly walk off it (had a baby and 2 toddlers as well!).
I was in pain for a couple of weeks, then booked an osteopath appointment. Fortunately, one appointment had me skipping around pain free again. Total cost to me was about 60 pounds.
The bus driver was a young girl, who was obviously terrified that I would complain, and she would lose her job. When I saw her again some weeks later, she asked how I was, and I said Fine, don't worry!
I didn't sue, because there were no lasting effects, and I just thought, ok that's life.
I just didn't feel angry enough to sue.
More recently, I had a very expensive dental operation, that went completely wrong. Afterwards, I discovered that this dentist has a history of incompetence, and of being sued. Now, in this case, I am suing to get my money back, because it cost around 2000 euros, and I had to get it done again, for a similar cost, and also I had 3 weeks of excruciating pain (24 hour Ibuprofen for 3 weeks is no joke).
Hope these 2 stories might help him make up his mind.