The most important rule we learn in Geology is "the past is the
key to the present". So, it is useful to look at occasions where
history repeats itself to understand current events.
The last earthquake of Mw>=6.5 in the general region of the
Mw 7.1 New Zealand earthquake of 21 August occurred on Feb 10, 1995.
This earthquake was followed on Feb. 16 by a Ml 3.6 near San Juan
Bautista, N.Z.
In 1951, an Mw 6.5 in this area of New Zealand on April 23 was followed
on April 27 by a swarm including a Ml 3.8 and Ml 3.1 in San Juan
Bautista.

This makes some sense from far-field triggering point of view
since the fault here is aligned so that incoming waves from
New Zealand would arrive with their wavefront parallel to the
fault, affecting the fault simultaneously along it's length.
This might lead to larger than normal earthquakes if strain
is added simultaneously along the fault rather than in segments.

So, can we learn from the past?

I wonder if that is what Don is doing to make his successful
predictions. He has said that his technique is related to the
far-field aftershock idea. After the New Zealand event, he
predicted an earthquake west of L.A. Is there evidence that
this area is triggered by earthquakes off the east coast of
North Island, New Zealand in the same way as earthquakes at
San Juan Bautista may be?

Looking back through the data, the last three such earthquakes
occurred on 23Apr51, 13Feb38 and 5Feb95. These were followed
by earthquakes of Ml3.2 near San Fernando, CA on 25Apr51,
3.5 near Inglewood on 14Feb38 and a Ml 3.4 near San Fernando
on 9Feb95. Since history often repeats, it seems Don's forecast
may be on target for the area west of Los Angeles.