Summary:
We say regarding קנס and בו"פ that they are given to the same party only after we have established this rule that it all belongs to the father.
But if not for this, I would have said, even a minor, but it is written, ‘if it was true, etc.’ - הא לאו הכי הוה אמינא אפילו קטנה והכתיב אם אמת היה וכולי
Summary:
We can distinguish between a מוצש"ר (where there is a difference whether she is a נערה or a קטנה) and הבא על נערה המאורסה, either based on the פסוקים (whether it is נערה or נער), or based on the logic the פיתוי קטנה אונס הוא so he is not really a מוצש"ר.