Expression: 'She reported (his) having seen the gunman.'

[Tom]

Hi

The Oxford Advanced Learner's Dictionary writes in one of the examples:

'She reported (his) having seen the gunman.'

Since the word is in brackets, it's understod that it's optional. Shouldn't it be (her) having seen the gunman?

Tom

PS: Is my blue comma correct?? :roll: :roll:

[Conchita]