"It would have been very difficult for her to see him," the detective said.
It wasn't immediately clear how fast the motorist, a 69-year-old woman, was traveling, but she was not believe to be at fault and was unlikely to be cited, police said.
Harrison said he routinely tells his photographers to be safe when they are working.
"In any job you have to exercise a degree of common sense and caution," he said.
Harrison hopes celebrities and paparazzi examine their actions to ensure a similar event doesn't happen again. No photo is worth someone's life, he said.
"Everybody wants to be the first one to get that shot, get that scoop," Harrison said. "But at the end of the day, you can't spend money if you are dead."
Associated Press writer Robert Jablon contributed to this report.
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