The following excerpt is from an article about a film director from the Washington Post, written by Amy Nicholson:
Overnight, she became a major Hollywood contender, but then she fought, and lost, two bruising rounds against the studio system when her big-budget follow-ups flopped for reasons outside her control.
Should it be "outside OF her control"?
Although omitting the 'of' sounds OK in a speech form.
Is this an exception to grammar rule that I don't know? Or just a stylistic choice?
If I were the writer, I would have included the 'of' which is not wrong, am I correct?