Any roller coaster can cause a blackout. There are a number of factors that go into it, such as coaster g-force, outside temperature, and hydration of the person riding. If you have a dehydrated person riding a roller coaster in 100 degree heat - you can bet they are going to black out!
That was my case when I rode Laser at Dorney Park in 2005. It was 102 degrees out, and I had not been drinking my share of the water. I had total vision loss from the first loop to the final helix. I have ridden Laser and similar loopers since with no problems whatsoever - it was just at the time I was not fit for riding.
