This is how I interpret it. Watson's medical issues originate from himself, which is why they vanish once he's in on the action. They're also literally a precondition in the medical sense, like a pre-existing condition, which maybe doesn't quite conform to Dramatica's definition, but it is cute.
I have a couple of final things that are niggling at me.
First, how do we interpret Consequence of Conscious/ Contemplation?
Second, this story bears many similarities to The Silence of the Lambs, which we've remarked on before. The story begins with an active serial killer, a brilliant but socially objectionable expert is brought in to assist the investigation after a new crime in the series is committed, the relationship between the expert and the investigators sours in the third quarter, the OS is brought to an end by a one in a million gunshot.
I see these similarities, and I start wondering why our concerns are different. What makes "A Study in Pink" Present, and The Silence of the Lambs Progress? I'm guessing that it's because "A Study in Pink" doesn't have much in the way of a supervisor type character demanding results, while TSotL has Clarice's boss and the senator. Plus, in TSotL the victim is still alive, so it puts this sort of ticking clock aspect into it. I guess "A Study in Pink," when it comes down to it, is all about the investigation of a single crime scene, and that part of it all takes place over the course of a single day.
Any expansion on this would be really helpful to me. I find OS Situation Concerns to be difficult to recognize in general, but especially Present. There are only twelve stories with this OS Concern in the database, and I admittedly am not helping much by only having seen two of them, both years ago.