[Robert A Cook PE]

Odd.

After any 5+ magnitude quake, is rare NOT to have aftershocks!

So what is this scientist referring to by claiming a "coincidence" of two earthquakes in the same area?

[bd476]

It seemed strange that they called the two quakes a coincidence.

Perhaps when there are two distinct fault lines involved they give each a unique "quake" status. Then "fore" and "after" shocks would apply only to precedent or subsequent quakes occurring on the same fault line.

Just a guess however.