Doesn't matter if he told them that the bracelet was wrong. He decided that he could not trust the hospital and that he wanted to leave. Seeing as he wasn't under a psychiatric hold, they had absolutely no right to do anything but ask him to sign a release, which of course he isn't obligated to do either.
I mean, what if he hadn't woken up? Are they going to start prepping him for surgery, maybe place him under anesthesia before they realize what went wrong? Seeing as according to the complaint, the first thing he told the nurse is that they had obviously mixed him up with someone else, and she apparently wasn't smart enough to simply apologize and offer to fix it, but rather ordered security to hold him in the hospital when he wanted to leave.
Read the story, read the complaint. Its not just two security guards (and for the record, he makes it clear that one of the guards was apparently not happy with what the other was doing), but also their boss, a nurse, her boss, and possibly another hospital administrator that all should be arrested for unlawful imprisonment and have their royal behinds sued into oblivion.
If the nurse had never called for security in the first place, this never would have happened. Although they obviously overstepped their bounds, I have to look at this from the viewpoint of the security guards too. They were called to a scene by a nurse who asked them to restrain a patient. In this case, do they even know any better than to just do what the nurse asks. They might think he's a psych patient, they might think he's a criminal, they don't know. To top it off, the administrators offered him pain meds...any pain meds he wanted. I think the feds ought to step in here and shut down this whole hospital. Bad at every link in the chain there.
Unless he literally just made up this whole thing, I don't think I can see the hospitals side. He wanted to leave, you let him leave, end of story. The second you hold him in the hospital everyone involved was committing a felony.