I hate to comment on RO's personal tragedy. I've tried to avoid it but given that he is putting it out there in public repeatedly, I feel it is okay to comment.
Fr RO posted a bit on the Goetia today. In that post he said, "It wouldn't have mattered if I were using Agrippa's Spirits of the Planetary Tables, the Archangels of the Spheres, or lighting candles in front of icons of Saints. Any system that I used and gave such generic and open-ended direction would have as much potential to burn down the house. Magic isn't a fucking game. I played fast and loose, and I got burned. That's how it works."
I would disagree. It is very unlikely that contacting a undine (water spirit) will result in your house getting burned down. Flooded maybe, but not burned down. While that is a bit tongue in cheek, the point remains that a given class of spirits react in ways appropriate to that class.
The Goetia are not whole spirits. They are not gods. They may be remnants of a god's nephesch or maybe even their ghosts. However, they are not gods. They are fractured spirits of some kind. At best they are not on your side because they are ignorant of your needs but their ignorance can be harmful. Even if they want to help, it comes out like your grandma obligating you to go on a date her next door neighbor's kid whom she thinks you are too shy to approach. The truth is you have no interest or worse, dislike for this person. Grandma means well but you're in for a rotten evening.
At worst these spirits are out to do you harm and will do so at any given opportunity.
The magician's job, should he evoke one of these, is to educate the kind ones in a proper relationship to the magician. In the case of a harmful spirit, the magician's job is to control it. Perhaps in time a proper relationship can be formed but make no mistake, this fellow is not your friend.
The first sign of a goetic spirit working going awry is obsession. The constant need to work with the spirit, give it energy, give it praise etc. This is what will get you burned eventually. This can be seen in ROs work by simply reading his blog. The error was in the obsession. The obsession led to playing fast and loose.
A more subtle sign is forgetting it is present at all in your life. Untended gardens grow weeds. Untended demons crack the asphalt and allow weeds to infiltrate your foundation.
He is correct in that open ended generic directions are problematic. He is right that any class of spirit can manifest harmfully. However, classes of spirits tend toward their average behavior. The average behavior of a demon is, well, demonic!
I love RO's work and RO has been a great help to me and I am not putting him down. Mistakes happen. Magicians rise above them. Show me a magician that hasn't erred and I will show you one that hasn't done more than read a few books. We all create our personal abominations. It is part of the work and I respect RO for doing his portion of the work. However, the spirits of the lesser key are dangerous and should be handled with care.