That is male.
The dot you are normally looking for is the epiandrous fusillae that would be on the epigynal plate. There is no dot visible there in this pic, nor is the dot that is present really a way of sexing this as male.
The reason I can say with reasonable confidence that this one is male is because at 4 inches, the epigastric furrow of a female will be very evident and distinct from a male. If this were a female, that white "dot" you see would outline nearly the entire furrow, and would be much wider.
In addition, it looks exactly like my male ventrally, and NOTHING like my female, who is about the same size. Here is a close up image showing the difference between my pair.
Here is the male at a less magnified range. Look familiar?:}
BUT like I said in your thread, it's hard to see these things clearly in photos, so molts are the way to go.
But if I were a bettin' man, I'd bet on male!