https://www.si.com/mlb/rangers/game-day/texas-colorado-rockies-home-opener-controversial-slide-rule-mitch-garver#gid=ci029e7957e00026ec&pid=usatsi_18068977
“The rule states that the runner sliding into second base has to maintain possession of the base," crew chief Bill Miller said in the Pool Report. "This runner did not maintain possession of the base. And he not only did not maintain possession, he came off the base and made contact with the fielder above the knee. That constitutes a violation on two terms."
Miller added, “I’ve never had a game end like this. And it’s the first time I’ve been announcing over the PA system. So, it’s all new to us. It’s an unfortunate way to lose, but those are the rules.”
Over the PA, the ump said "there was a slide rule violation, the runner at 2nd base is out, the runner at 1st base is out." It would have been nicer if he had stated the possession of the bag and contact above the knee over the PA.