Ah yes, conspiracies are all around us.
The refs performed by the book (the rule book and instructions) in this sequence. The lead ref's only focus is on whether or not a TD should be awarded. The 2nd official generally is watching the wrestlers. However, at the end of the period his bigger responsibility is to watch the clock AND the lead ref. If there is a question as to whether the points were awarded before the end of the period (which there would be in this situation), then the 2nd official is supposed to offer his opinion. In situations where the awarding happened within a second or so of time running out, and it's not possible to know for sure when criteria was met, or when the points were awarded with regards to the clock, the refs are instructed to review the video on their own. It's not a challenge -- it's getting things correct, and their review had nothing to do with whether or not tOSU was out of challenges.
Everyone is entitled to their own opinion.
Two college refs, with tons of experience and who know the rules inside out, reviewed a video of the sequence. They determined that criteria was not met for a TD. I trust their analysis.