1)  The son puts the taxable scholarships on his tax return.  But his income is below the threshold so he is not required to file.

Why is the parent not claiming him as a dependent?  Is the parent ELIGIBLE to claim the child as a dependent?  If the student had qualifying tuition, would the parent be able to qualify (such as their income) for the American Opportunity Credit?  Any chance the some of the scholarships are Pell Grants (or other scholarships that are not restricted to only tuition)?

2) Was the $6000 paid in 2024?  Or was it paid in 2025?  You may need to get the printout from the college that shows the 'financial account' of the student that itemizes all payments and expenses.

A parent can not 'let' a child to 'claim themself'.  If the child is ABLE to be claimed as a dependent, the child needs to indicate that on the tax return.  There are certain situations that if the parent chooses not to claim the child, the child may be able to get limited tax credits for education.

Is the parent ABLE to claim the child as a dependent?  If the student had qualifying tuition, would the parent be able to qualify (such as their income) for the American Opportunity Credit?  Any chance the some of the scholarships are Pell Grants (or other scholarships that are not restricted to only tuition)?