Of course it is a calculated risk, however as a T1D myself, you can't ignore the fact that the current FDA approved pumps are also very dangerous. Pumps that don't respond to dropping blood sugars (most of them on the market today) and keep delivering insulin when you don't need it, compound low blood sugars, which has personally got me into serious trouble many times. Picking between a FDA approved "dumb" pump running on 10 year old software versus an open source option that explicitly has code to stop insulin delivery when blood sugars fall, seems to be an obvious choice. I've had diabetes for 31 years and this is by far, hands down, the greatest advancement I've experienced.
I'd love to see some real data from San Francisco as well, but I'm almost certain San Francisco is well above capacity. The following article points out some interesting facts about vehicles in motion in relation to gridlock. Unregulated ride sharing is definitely having an impact, how much is the question.