We were told to do the research to show this is in fact the case:
http://www.poopflingingmonkeys.com/eq/osw/sky.html
"Until the triads are down the guardian will constantly respawn as well if you kill him (same for the Lord, who will respawn right away if there is a mob still up on the island)."
http://mysite.verizon.net/drexxell/eq/planeofsky.html
"Q: Who can you spawn here without leaving the island?
A: The Spiroc Lord. By killing "The Spiroc Lord" while "The Spiroc Guardian" lives. "
http://web.archive.org/web/200112171....htm#itemsdrop
"And, killing the Spiroc Lord before killing the Spiroc Guardian will make the Spiroc Lord respawn instantly. It is thus possible to farm the Spiroc Lord for the drops and the rare quest items."
http://web.archive.org/web/200110291...r/EQ/skyguide/
"The Spiroc Lord will respawn if Spiroc Guardian is still up."
This was never changed in classic. Thanks!