Had

I get confused as to whether or not to put "had" sometimes. Take this as an example:

As he walks back up the aisle, the guy who said 'wow' throws a stone that hits him right on his left cheek.

Should there be a "had" before "said," since he said "wow" earlier on, or is it not necessary when speaking in present tense like that, i.e., with "walks" rather than "walked," and "throws" rather than "threw?"

Thanks.