Yeah that definitely seemed like a trip especially from the angle of the 2nd video Morrell landed a punch on his shoulder and Benavidez tripped over his foot.
It was most definitely an off balance trip but Benavidez didn’t seem to complain about it. He probably knew that he was well ahead and that the “knockdown” wouldn’t make a difference.
The punch caused him to trip and his gloves touched the canvas so technically that’s a knock down. But Benavidez was not stunned or hurt.
The foot caused the trip. He tripped over his opponents foot as a fact, so not sure how it can be a legit knockdown.
Sad part is this fight had replay where they can look at stuff like this. Like a headbutt that caused cut or a slip being ruled a knock down. They reviewed this and called it a legit knock down. As for Benavidez not complaining he did. He also jumped on Morrell when the fight continued. He complained at the press but since he won he didn't make a big deal out of it.