So in other words, an accident was counted if a driver had a brief conversation, hung up the phone, put it away, drove five miles, and then was hit by someone running a red light. It's pretty easy to see that this accident would likely still have happened without the phone usage. What's not clear is what percentage of the accidents are like this.
That's a bit of a stretch to say the accident would still have happened. When an accident occurs at a particular time it's because of a huge number of variables coming into alignment. Shift one of those just slightly and the accident won't occur.