***The one big downside, is when you get sick and need to leave early. Even worse, is when the driver gets sick and has to leave early. There are others as well but those are the worst.***
Sure it could be worse:
The driver gets sick and goes to work and gets you sick too.
The driver looses their keys.
The driver gets Explosive diarrhea in the car.
You get Explosive diarrhea.
I used to ride share, and 1 of the 2 last items and your list happened. Thankfully it wasn't the last one.