IRS liens, liens from municipalities, HOA liens, judgement liens from child support or alimony might not be attached in a way that's obvious and can appear after closing...

You would need to get a court judgement to determine if the tenant is responsible for damages beyond the deposit amount in order to collect any further money. 

I know in many places here the landlord has 30 days to send a final judgement.

I don't have much experience with laws in Oregon as to what I need to have before I can sue, I don't think I need a judgement but I am not sure.

This tactic also keeps the building in dept as a form of protection, if there is a law suit ( and they can not get to you personally) there is no money in the property for them to go after. they may get some sort of judgement on the building, but by pulling the money out all the time you are getting what you can before anything like that happens.

Passion can cloud judgement.

Once you get a judgement, then pursue collecting it.

Exactly where is a judgement call between Agent & Seller.

This not only involves what you are owed, but whether you can obtain a default judgement against a borrower and a host of other legal questions. 

Also, on top of this the seller has been flipping other houses (No judgement) but we keep getting pushed to the back burner every time.