Since I wrote that query back in 2005, and it was actually somewhat more complex (had to deal with users banned after they dug the same story as you for starters) I assume Ian (whom I've never met) is simplifying for pedagogical reasons. And we had something similar to what you describe in no. 2 in 2006.
Also I find it fascinating that the table is "Diggs" (it was originally "digs" and I suspect it still is). Gotta get the branding right, even in sql queries.
