Yeah, tOSU was what pushed the B1G "over the edge", They are the "big name school". But without Nebraska going rogue, the B1G may never have been forced to make their vote results public and tOSU may not have decided to start pushing back themselves.
I see it is as similar to what apparently happened with the PAC vote. The initial vote to play wasn't unanimous. When that happened, Utah said they'd go to the Big 12, which caught everyone's attention. But when USC said they'd go independent, the PAC decided they'd re-vote and that one was unanimous.