Exactly. I don't remember reading that. I don't think it was even inferred.
Decoy implied it.
Either way, it strikes me as a cathartic match up. The Goliath Scorpions let their scientist caste do the same thing the Coyote's scientist caste did and were given every opportunity to put their house in order. Not to mention the Goliath Scorpions oversaw the cleansing of the Coyote clan.
A member of the Coyote scientist caste was elected Khan thereby giving them (and by extension the Society) effective control of the Clan.
(Side note: It is one of the many issues I have with WoR, most of which revolve around individuals, if not entire Clans, acting against their established character but was allowed because the author was given free reign as long as the desired end results were reached. I mean seriously how is a member of the scientist caste even eligible for becoming Khan in Clan Coyote? After all they weren't the Diamond Sharks.)
It was just after the Wars of Reaving, everyone was still uncomfortable with the Society's gene games, what the Scorps did would be fine if it weren't for that, so the Cobras heavily trumped it up to paint the Scorps in an evil light and do them away with.
Don't forget why the Reavings started in the first place. The ELH DNA was tainted by the Grand Council's established standards and should have been disposed of. When questioned about the ELH members adopted by the Scorpions, they replied that they had all either been killed in combat or tested out of the warrior caste. Instead the Scorpions were secretly looking to introduce their genes into their gene pool. They were at the pinnacle of their power, but were impatient and got caught with their hand in the cookie jar.
They should have hidden the ELH genes away and waited a couple years for the situation to stabilize before starting work on the genes. Instead they started working on them while some of the surviving Clans were still looking to strengthen their blood pools which is why the Cobras attacked in the first place.