The first part is correct, but not for that reason. Even if you had been the recipient of the 529 funds, instead of your kid, you could not "apply any of the 529 withdrawals to cover this 10k".
The 2nd part is not correct. The 529 withdrawals are not fully qualified. You have already used the entire $30K in expenses to avoid penalty on the first $30K of the IRA withdrawal. You cannot also apply those same expenses to the 529 withdrawal. $10,000 (the 40% of the $25K due to earnings) from the 529 plan will also be subject to a 10% penalty in addition to the tax due on the 40%. The penalty is due because you don't meet one of the exceptions (tax free scholarships or claiming a tuition credit),
Room & board are qualified expenses for the IRA exception and 529 plan withdrawal, even though they are not qualified expenses for a education credit.
