You're missing the context here. The assistant ref can not award a TD during the match, and makes no type of signal to indicate during the match that he agrees with a call. So before they look at the video, the head ref asks the assistant what he saw. The assistant is quite experienced (worked as many matches as head in NCAAs), so the head ref wants his take on the sequence being challenged, before they begin the video review.
The process is that the two refs then watch the video, and look to see if what was called was accurate, or if on video there is clear evidence that the call was incorrect. There were calls overturned in NCAAs. The refs want to get the call correct. They make the best decision they can in real time, and if challenged, or if they elect on their own to review the video, they will overturn it if there is clear evidence that the call made in real time was incorrect.
I doubt that the decisions by independent reviewers in wrestling video reviews would be much different than the decisions made by refs reviewing the video of matches they were calling. Most of the calls are pretty easy to make, both on the mat and in video review. In a tournament like NCAAs, where the talent level is so high, there are always going to be some calls that half a room or refs would call one way, and the other half of the room would call the other way. It doesn't mean that either opinion is wrong; just that some of the situations being evaluated are so nuanced, and so rarely encountered, that they are really tough situations that could legitimately be called either way.
(To expand on this a bit, I've been in a lot of these rooms. A video sequence will be shown, and the presenter will ask how many would have awarded X, and how many would not have awarded X. It's not unusual for a large number to ask for the video to be replayed (which you don't have in real time). After the replay, the vote may be 60/40, 70/30, 50/50, and even 95/5. The presenter will then work through the sequence, showing it in slow motion, and also pointing out various criteria. At times, they'll also ask additional questions. The goal is to get the entire body of refs to, after discussion and reflection, come to the same conclusion, and to also realize where they were making a mistake if they voted the wrong way. It's really, really interesting when in a 95/5 vote, it turns out the 5% are correct. The 50/50 votes usually take a lot of back and forth discussion, clarification, etc. Keep in mind, these videos are usually on the most challenging situations wrestling refs ever face.)
FWIW, the current NCAA rules do not allow for independent video review at tournaments. They do allow leagues to have independent video review for league duals. The B1G used independent video review in 2017-18. I did not check on whether or not they used it in 2018-19.