Based upon the facts you've laid out, I do not see how you would have known, or should have known that this oil drum would be spilled by your tenant.As many have pointed out above, this analysis could change dramatically if you told your tenant to move it, you gave him permission to move it, or if the oil drum had some sort of defect in it and you knew about it and that contributed to the spill. 

I also said he was more than welcome to put something over it or fix it with his own money, with prior permission.

They knew the lease said they needed permission. 

If they can walk, that's ideal, or an easy bus or bike ride, assuming parking is a pain at the university.Loyola law school has a part-time program, so I'd focus on Tulane U.Furnish the rooms, make sure you rent a quiet apartment, get permission to do this of course, then advertise ONLY at the law school, so you don't have to deal with non law student applicants. 

On it, they grant permission to contact landlords and references.  

They will provide you with a sample consent form - or wording for your consent form - to obtain the candidate's permission to pull their credit history.Alternatively, you can use RentCheck in Canada, but it may take a little time to have yourself or your company vetted to establish service.Checking the criminal background on your Canadian applicants is another matter.  

I was going to tell them that we will continue to provide 24 hour notice for showings, but from now on we won't be asking permission we will just be advising them that people will be entering the property. 

I gave them written permission to have a long term guest over the summer.  

Rent a 2 or 3 bedroom with your gf, with permission to sublet to a roommate or to AirBnB the extra room. 

They never sent us work orders and get our permission before fixing things.