Wow, Brett. A very impressive case. You chose exactly what I would have chosen, and it's clear it was the right choice, given the obvious improvements.
Lingering discomfort, as evidenced by the half-hearted continuation of the previous kicking, may be addressed potentially by acupuncture (e.g., at BL 28, GB 30 and any A Shi or trigger point that could conceivably release a muscle band that is clamping down on the sciatic nerve); and/or chiropractic (with particular focus on the sacro-iliac joints on both sides).
I would continue the herbs, yes. If the owner is concerned about cost, try a lower dose. If it was just that he accidentally ran out, then I would continue at the full dose until the kicking has largely resolved. That might happen with the next chiropractic/acupuncture treatment.
One last comment. If you're using Natural Path, because the herbs are twice as dense as regular granular extracts, you can give half the dose he's on now and still achieve the same dose level as with any other manufacturer's granular extract. If it's a hassle to give so much, that might help.
Keep up the great work, Brett! You're almost there. A very satisfying case for you, I'm sure!