Research/academia can certainly be kind of screwed up, but I doubt that any ethics board in a developed country is going to okay a study that involves tricking people into a spinal tap. And all the consent forms patients are asked to sign before agreeing to a procedure, the ones that tell you about the procedure and the risks in excruciating detail, are as much for the protection of the doctor as the patient. That way, if the patient ends up paralyzed, at least they can't claim you didn't warn them when the case goes to court.

So unless you were dealing with a single rogue Mad Scientist, I'd assume that was an error.