Pain Clinic and what can happen?

I know a person that use to be a drug addict and was an alcoholic as well. Last year he got really sick and the doctors gave him less then a 5% chance of making it threw the night. Well to make a long story short he mad it and is now having pain and is being managed by a doctor with Morphine 15mg three times a day. He has stopped drinking as they told him if he had one more drink it would kill him as he has a hole in the middle of his pancreas's and that is what he is having the pain from.He takes his Morphine more often then he should and then gets other meds from people off the street as to, vicodin, xanaxe, methadone, percocet, ambien or whatever else he can get his hands on. When I started at a pain clinic they drug tested me and I had no issues to it as I only take what the doc perscribes for me, but I tell him that they drug test and if you come up dirty they will not see him and they wont perscribe meds to him anymore but (as to what I understood when I was being seen by a pain clinic) and his primary doc is in a free clinic that usually does NOT prescribe narcotics out to patients that are seen there but they are with him because of his condition and they said its a very rear thing for them to do. So my question is will they see him at the pain clinic if he has many other drugs in his system that are not prescribed to him as he is telling me that he doesn't believe me,