"It may have been a comedy, or it may have been a tragedy. It cost one man his reason, it cost me a blood-letting, and it cost yet another man the penalties of the law. Yet there was certainly an element of comedy. Well, you shall judge for yourselves."
Ever realize that you are Canonical before?
Our old pal John Watson speaks directly to us in that opening of "The Adventure of the Three Garridebs," asking us to decide something for him. He thinks this might be a funny story, but whether he's unsure of his own ability to tell the joke or just concerned about how some of us might take his getting shot or Nathan Garrideb winding up in a nursing home. But in his own mind, the events of "Three Garridebs" was funny enough that he has to at least mention that there was comedy there.
Maybe he's just giving us permission to laugh at this particular criminal matter before we get to the serious parts. Because even Sherlock Holmes, both before and after Watson takes a flesh wound, has to laugh at parts of it.
This is the tale where we get the phrase "crazy boob of a bug hunter." We get a visitor showing up at Baker Street who recognizes Sherlock Holmes from his pictures (perhaps one of the reasons Holmes retires not so long after this). We get that lovely quote from Holmes that could be used very neatly of late, "I was wondering, Watson, what on earth could be the object of this man in telling us such a rigamarole of lies."
Rigamarole. Sherlock Holmes says "rigamarole." If you're in a state where pot is legal, you can probably get ten minutes of giggles our of that word alone.
And a villain who says things like "Here am I, a wandering American with a wonderful tale," and expects people to take him seriously, something Sherlock Holmes doesn't from the outset. And once he's caught, even after shooting at Watson, admits, "I'm a soft-hearted guy that can't begin shooting unless the other man has a gun also." And follows it with "I've not hurt this old stiff."
As "The Adventure of the Three Garridebs" wasn't published until twenty-two years after it occurred, and Watson refers to Nathan Garrideb as "our old friend," there seems a likelihood that Watson, and possibly Holmes, continued to see Garrideb once this case was over, which is perhaps where the "cost one man his reason" part came in. With the sanctum of his home and collection violated, there's a strong chance Garrideb started seeing intruders and threats to it everywhere and coming to 221B Baker Street over and over again as a returning client, to the point where Holmes and Watson saw him as a bit of a joke. (And, perhaps, gave Sherlock one more incentive to retire to Sussex.)
But there was something Watson found very funny in all this, hence the words at the outset, yet, as with all comedy, might not have been sure everyone would laugh at it. With all the other funny moments in the Canon, this is the one time he thinks it funny enough to call it out, though, which gives us a hint as to where the doctor's funny bone truly was.