This situation is exactly why I use a helmet light in addition to one on my handlebars. With a helmet light, you simply glance at cars that look like they might pull out or turn in front of you. When I give drivers a "laser stare" with my helmet light, they stop in their tracks, every time.
It's easy to draw too many conclusions from accidents like this. How many people say they are going to quit driving cars on the roads after getting in a car accident? There are thousands of car accidents every day, many that kill and seriously injure drivers, yet you don't hear people saying they should quit driving because it is too dangerous. The same goes with bike paths. You can get hurt on a bike path just as easily as on a road, and I would venture that it is perhaps more likely on a MUT. Runners wearing earbuds, kids riding bikes, moms pushing baby carriages, walkers with dogs on leashes are all accidents waiting to happen when cycling on MUTs.