If the 50% down payment was a gift, or if it was a loan that you intended to pay back (and actually do pay it back), then there's really no issue with you claiming 100% of everything. Now if it was a gift, and that gift exceeded $17K in 2023, then the giver of the gift (your dad) will need to file a gift tax return IRS form 709 with the IRS. Take note that "NOBODY" will be paying any kind of a gift tax. It's just a legal reporting requirement that needs to be met.
So, if the 50% was more than $17K, if the form 709-Gift Tax Return is filed, that will help to "substantiate" your full claim to all the income, expenses and depreciation.
If it's a loan, then you'll need documentation between you and your father to prove it, in case you're ever audited.
Typically, I would see no reason for an audit unless there was something that "stuck out" on your return that got it flagged, or you have the experience of being one chosen "at random" for an audit for that particular tax year.
